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Lessons on strategic stability and SSBNs from the Cold War

Published 12 Dec 2014 13:51   0 Comments

Admiral Sir Mark Stanhope (Ret.) is a former First Sea Lord and Chief of Naval Staff, Royal Navy. This is an extract from a presentation to a Lowy Institute international workshop on sea-launched nuclear weapons and strategic stability, held in Singapore earlier this year.

The role of nuclear ballistic missile submarines (SSBN) in strategic stability may seem obvious. However given developments in the Indo-Pacific, including progress in the Chinese and Indian SSBN programs, now is a good time to examine this scantly explored area. 

The SSBN HMAS Vanguard returning to HMNB Clyde, Scotland, 2010.

I have been asked to offer some insights from the Cold War and more generally from the British experience of operating an SSBN fleet.

It can be argued that the very existence of SSBNs, which provided a 'second-strike capability', was essential to the strategic stability achieved through nuclear deterrence in the Cold War. Before the introduction of SSBNs, the deterrence philosophy of 'mutually assured destruction' hinged on a 'launch on warning' mechanism, which involved both sides launching their nuclear weapons at the first sign of a detected nuclear strike.

Second-strike capabilities like the SSBN introduce the concept of a certainty of retaliation and eliminate the need for a launch on warning system, since any first strike is not capable of removing these 'invulnerable' weapons. Even when the 'Star Wars' missile defence debate was at its height in the early 1980s, the fundamental assurance of an invulnerable second-strike capability was not questioned.

But how invulnerable are these platforms today? [fold]

While science moves on at great pace and solutions for submarine detection are sought through non-acoustic means (for example, the use of satellites), sound in water remains the prime detection mechanism. All of us in the anti-submarine warfare world have been fighting with the physics of this since the advent of the submarine over 100 years ago.

It seems clear to me as a practitioner that noise quietening and signature reduction of nuclear propelled platforms remains the engineering challenge (and cost) that will continue to drive invulnerability. I consider it will continue to be so for some time yet.

Deterrence is about perception and an understanding by each side that there is a certainty of catastrophic retaliation. This certainty, when provided by the SSBN, is made up of a number of separate elements. The first consists of the technological capabilities of both the weapon system and the submarine supporting it. These include design, manufacture and build, engineering readiness, maintenance, sustainability, reliability and a continual need to demonstrate that it all works.

Then there is the human element, which includes not only the 'will' of politicians and state leaders to actually use the system, clearly a fundamental requirement of deterrence, but also the certainty of response by the people involved. This human element includes an enormous training load for everyone, including submarine crews, nuclear propulsion engineering support, missile and warhead maintenance staff and many more specialisations. There is also the need to foster an ethos in the delivery of the capability and to ensure the dedication of all those working within it. All of this places huge, unique and costly demands on the nation and workforce.

The practical realities and challenges of these technical and human issues cannot be over-emphasised. If the whole nuclear deterrence philosophy is about a perception of certainty, then it will only work if that certainty is underpinned by the professionalism needed to operate the SSBN and its nuclear weapons. 

The Cold War taught us that you have to work hard and spend a lot to maintain the invulnerability of the submarine platform and thereby the second-strike capability.

Assurance is required after each SSBN patrol that detection by the opposition has not taken place and that the submarine has retained the necessary material and personnel readiness to fire its missiles, if ordered, at any time during the patrol. Throughout the Cold War this readiness was measured in minutes.

Each patrol was (and still is) analysed in great depth using onboard recordings and other sources of intelligence to provide the necessary critical assessment of success. This after-action analysis makes a fundamental contribution to strategic stability and is also an important reassurance to political leaders.

I am not at liberty to talk much about the 'firing chain' of decision and authority, other than to highlight the importance of its structure — both in technical and human terms — to the credibility and accountability of deterrence. It has to be 100% secure from the actual issuing of orders themselves through to the assured communications link to the submarine and the missile-firing interface. And it needs practice and regular testing.

More broadly, it is no good simply training and exercising when working in the nuclear dimension. Absolute assurance of the safety and reliability of procedures and processes is necessary.

All nuclear activity is therefore underpinned by a quality control regime and constant qualification and re-qualification of operators. This fundamental requirement is a huge burden and takes considerable time, cost and effort. There are no shortcuts; it is a doctrine in and of itself and a considerable, but necessary, constraint. It needs to have built into it the reality that failure sometimes occurs, bringing with it the need for more time, training and examination. 

Lastly, getting a vulnerable 'when in base' SSBN to the deep sea, where it will become invulnerable, is a period of considerable risk. During the Cold War, this strategic vulnerability was principally overcome for the West and East through the adoption of the Continuous at Sea Deterrence philosophy or CASD. The idea of CASD has a built-in advantage for strategic stability. It is about the permanent presence of second-strike nuclear deterrence at sea. It has not been rushed to sea at a time of growing crisis, thereby aggravating and escalating a tense diplomatic environment. 

Of course it must also be recognised, with my Cold War comparison, that we were primarily in a bipolar deterrence environment, with simple binary statistics and capabilities that needed to be balanced. As nuclear states in Asia transition towards greater second-strike capabilities, they face the added challenge of multipolar nuclear deterrence, where confused messages may be worryingly easy to generate.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Photo courtesy of Flickr user UK Ministry of Defence.

Misinterpreting China's nuclear posture

Published 28 Oct 2014 15:18   0 Comments

In this debate, both Thomas Mahnken and Elbridge Colby argue that a secure sea-based second-strike capability might embolden China to pursue a more aggressive foreign policy.

Their arguments are based on an article by Thomas Christensen, which drew the conclusion that China's nuclear strategy is based on a textbook of the PLA's Second Artillery Corps, Science of Second Artillery Campaigns, which calls for blurring the line between conventional and nuclear war.

Christensen's conclusion is problematic for several reasons.

First, the Second Artillery is responsible for implementing China's nuclear strategy, not making it. This is the responsibility of China's top political leadership.

Second, Christensen mistranslates a critical term and misunderstands the cultural context in which the textbook was written. Christensen interprets the terms of 'conventional war under nuclear deterrence', 'double deterrence' and 'nuclear forces as a shield for conventional forces' as if China would combine nuclear and conventional coercive means to achieve its diplomatic objectives. But the original meaning in Chinese is that if an adversary were to use nuclear forces as coercion against China in a conventional conflict, China would need its own nuclear capabilities to deter this potential coercion. [fold]

Rather than emboldening China to pursue a more aggressive foreign policy, a secure nuclear retaliatory capability will give China an equal footing in which to fight a conventional war with the US, where neither side could coerce the other with nuclear weapons. Recall that the direct driving factor of China's nuclear weapons program was the nuclear threats from America during the Korean War and Taiwan Crisis. China has already achieved mutual deterrence with America, and current China-US strategic relations are stable. However, US homeland missile defence has the potential to neutralise China's nuclear deterrent, and China may be forced to build up its nuclear arsenal in order to restore strategic stability.

Thomas Mahnken also mentioned the 'consequential' fact that China apparently, to some extent, co-mingles the deployment and command and control of its nuclear and conventional forces. While sharing his concern on possible escalation, two points have to be made.

First, China does operate both conventional and nuclear ballistic missiles, but China does not deliberately co-locate its conventional and nuclear missiles to confuse its adversary. Conventional and nuclear missiles require different operating sites, so technically it is not easy to co-locate them. Besides, co-locating different missiles to confuse the adversary would undermine the survivability of China's nuclear forces, which is not in China's interest.

Second, every country to some extent, including America, co-mingles the deployment and command and control of its nuclear and conventional forces. For example, America co-mingles the deployment of its SSNs and SSBNs, and US strategic bombers could be used for both conventional and nuclear purposes.

Potential China-US conflict escalation is a focus of current international relations scholarship. China is developing asymmetric means (in American terms, anti-access/area denial capabilities) to counter superior US military forces, and accordingly America is developing the Air-Sea Battle concept to address that. We should make it very clear that it is the interaction between these strategies that would cause escalation, rather than the strategies themselves. In order to understand the mechanism and try to reduce the escalatory risk, we need to analyze both sides' strategies and their interaction.

Simply blaming one side is not constructive and will not help.

Photo courtesy of Flickr user Chuck Hagel.

Political stability first, strategic stability second

Published 14 Oct 2014 11:39   0 Comments

The central purpose of deploying strategic nuclear weapons on SSBNs, rather than on other less expensive and technologically demanding platforms, is to assure the survival of these weapons in order for them to conduct a second strike. The rationale is that assured retaliation will dissuade a potential adversary from attempting a preemptive decapitating strike, thus contributing to strategic stability.

Iskander Rehman questions the applicability of this logic in the context of South Asian regional nuclear dynamics and the Second Nuclear Age. From an Indian perspective, with flight times of missiles from estimated launch locations to possible targets being so short — just a few minutes — there is no chance of success for a 'Launch on Warning' policy. Having adopted a 'No First Use' policy, the survivability of India's retaliatory capability is crucial, which means it has little choice but to put a certain number of its missiles on SSBNs.

Nobody has made the case that Cold War policies and scenarios can be cut-and-pasted into the Indo-Pacific scene. But a credible second strike remains a deterrent for states contemplating a preemptive first strike as much in the Second Nuclear Age as during the Cold War, and it is certainly a stabilising factor. As one contributor to this debate has noted, land-based missile silos, launchers and airfields are more vulnerable than SSBNs, and this vulnerability creates instability by tempting a preemptive strike. [fold]

As with any policy, there are challenges. Some include command and control, doctrinal and strategic development, engineering, design and quieting, and attaining and maintaining professional excellence and operating standards. But it would be wrong to assume that these challenges cannot be met, and cite them as destabilising factors. 

Impact of nuclear cruise missiles on stability

In an earlier submission, I mentioned the potentially negative impact on strategic stability of cruise missiles being deployed at sea. This is for several reasons. One is that the platforms (naval vessels) are dual purpose, in that they are also used for normal fleet operations and are thus equipped with non-nuclear weapons. This creates opacity and uncertainty in cases of encounters at sea between potential adversaries in conditions of heightened tension. Secondly, although technical measures can be built in to prevent unauthorised or accidental launch (as is the case with US Navy Tomahawks), launchers and control systems for the cruise missiles are often stored with the main non-nuclear armament of the platform, and such technical measures are likely to remain unimplemented. And thirdly, if the case of the Nasr tactical nuclear missile launcher of the Pakistan Army is any indication, the command and control of Pakistan's nuclear armed-naval units will be with the commander of the unit. Thus, launch authority can be delegated to a tactical level, lowering the nuclear threshold dangerously.

Pakistani strategy

Pakistan's apparent strategy is to rely on battlefield nuclear weapons such as the Nasr to counter superior Indian ground forces. The maritime domain has been added to this strategy, with the planned deployment of the nuclear-capable Babur missile at sea, ostensibly to counter India's naval strength. This provocative and risk-prone strategy is one which Iskander Rehman has appositely called 'nuclear brinkmanship'. 

Range of India's missiles

A few participants have rightly pointed out the short range of the K-15, currently the only sub-launched missile in India's arsenal. Quite obviously, to be an effective deterrent, India's SSBN the INS Arihant and her successors will need to be armed with missiles of at least intermediate ballistic missile range (3,000 - 5,500km). Until a missile with this range becomes operational, India's sea-based deterrent must clearly be considered to be in a developmental stage.  

While the deployment of specific weapons does have a significant impact, there are other factors that contribute to nuclear stability. The most important of these is the stability and maturity of the states concerned in the management of this capability. The India-China situation is not one to cause unease in the sub-continent at the present time. It is the India-Pakistan situation that is cause for concern, primarily because of the overriding influence and control of the Pakistani military in that country's political and security affairs. The egregious stratagem adopted by Pakistan, euphemistically termed 'sub-conventional warfare', promotes terrorist attacks periodically across the border under a virtual nuclear umbrella, and keeps the both countries constantly on the brink. 

Nuclear stability is a spin-off from political stability and depends on the will of both parties in any dyad to eliminate nuclear risks; this would appear to be the fundamental problem at present.

Photo courtesy of Flickr user My Past.

Strategic stability and SSBNs: Arms control may be the answer

Published 2 Oct 2014 11:18   0 Comments

From a strategic perspective, the bottom line attraction for states seeking to acquire nuclear ballistic missile submarines (SSBNs) is survivability. States possessing SSBNs cannot be victims of a disarming first strike.  They will always possess the ability to strike back with submarine launched ballistic missiles armed with nuclear weapons in order to inflict unacceptable damage on the attacking state. If this logic is correct, bilateral relationships will be stable because neither side will have an incentive to strike first.

Given some of the assertions in this Interpreter exchange on Indo-Pacific regional stability and SSBNs, it is worth revisiting two assumptions necessary to believe in SSBN survivability:

1. That they remain continuously at sea and;

2. They are very difficult to find once deployed.

Both assumptions are largely derived from the way the US and, to a lesser extent, the other powers possessing SSBNs — the British, French and Soviets — theorized about and operated SSBNs during the Cold War. [fold]

Yet for a SSBN force to operate continuously at sea requires at least three, but likely even more, of the platforms (depending on possible attrition during actual war) given deployment patterns. Neither India nor China are likely to possess sufficient numbers of SSBNs in the immediate term to operate continuously; in a simple sense, one vessel prepares to go to sea while another deploys and the third refits after its deployment. And of course, both countries must develop the training, tactics and procedures, not to mention maintenance and personnel policies, that would allow for this cycle over time. 

There are also reasons to doubt the assumption that SSBNs will be largely undetectable by adversaries in context of the Indo-Pacific. Indian and Chinese submarines, at least for the foreseeable future, are likely to be noisier than Russian, British, and French SSBNs, much less their American counterparts. Moreover, operational and doctrinal features of both navies may ease the inherent difficulties of detecting SSBNs. Both countries have a limited and well-known number of bases capable of housing them. Absent a larger number of hulls, both countries are likely to operate SSBNs in ways detectable to intelligence collection at the strategic and tactical levels. 

Indian and Chinese SSBN deployments are likely to spur greater efforts to develop anti-submarine warfare capabilities in many countries in the Indo-Pacific region. With a limited number of platforms, limited ability to spend time at sea, as well as command and control constraints (the importance of which has been raised in Ravi N. Ganesh's post), operational doctrine may derive from a modified version of the bastion concept used by the Soviets in the Cold War. Indian and Chinese SSBNs may remain in port until they 'surge' to pre-designated undersea bastions protected by anti-submarine warfare techniques and surface ships during crises. 

Aggressors may thus have incentives to attack adversary SSBNs in their home ports preemptively, as well as to find and neutralize undersea bastions. Unless China or India invests in large scale hardening — think U-boat pens in World War Two adapted to withstand nuclear and deep-penetrating conventional weapons — SSBNs will be vulnerable in their home ports, when transiting to and from those ports and likely, their bastions. 

Protecting bastions will be costly: China and India will have to improve their own anti-submarine warfare capabilities as well as devote a large percentage of their existing undersea and surface fleets to defensive measures. There are also opportunity costs; those parts of the fleet devoted to protecting SSBNs will not be available for offensive operations during crises. 

Further, if a nuclear state wants to protect against a disarming first strike, there are other potentially less costly ways of doing so. Existing or newly developed missile delivery systems (leaving aside air-launched weapons here) can be either mobile or hardened. Mobility and hardening at the very least introduce uncertainty into an adversary's calculations at, debatably, less cost and while leaving expensive and flexible naval assets available for other missions. 

Which brings me back to my original point about naval arms control. 

For those interested in strategic stability, not to mention peace, arms control remains attractive. In practical terms, there are remote prospects in the Indo-Pacific of achieving broad based disarmament for the three potential possessors of operational SSBNs, or in the case of Pakistan, diesel electric submarines armed with nuclear tipped cruise missiles.  Yet even during the Cold War, the US and the Soviet Union found ways to limit the riskiest forms of military competition. India, China, and Pakistan each possess sophisticated strategic communities well aware of the dangers of nuclear proliferation.

Thinking carefully about arms control measures for SSBNs — one of the most expensive and riskiest forms of proliferation — could begin the path toward to reducing military tensions across the entire region. Third party states like Australia and Japan affected by the nuclear rivalries at sea might provide good offices and perhaps even incentives to initiate arms control negotiations.

 Photo courtesy of Flickr user Official U.S. Navy Page.

Nuclear weapons at sea in Asia: A tentative concluding assessment

Published 30 Sep 2014 09:01   0 Comments

Most discussions about the security of Asia in the 21st century beg the comparison with the East-West confrontation of the 20th. In the nuclear realm, as in other domains, the question 'Is Asia different?' is central. Judgments on the stabilising or destabilising nature of Asian nuclear weapons at sea depend on a few key parameters, on which there does not seem to be major disagreement among contributors to the debate launched in this series:

  • It is generally agreed that secure second-strike capabilities at sea were a stabilising factor in the strategic relationship between great powers during the Cold war; there is no a priori reason why things would be radically different for Asia tomorrow.
  • Asian nuclear powers already have a modicum of secure second-strike capabilities. Through protection, mobility, concealment and deception, at least some of their land-based missiles are de facto immune to an adversary’s first strike. Or, to put it differently: no Asian nuclear-armed country could reasonably consider that it has a disarming first strike option on another.
  • Submarines armed with strategic (ballistic but perhaps also cruise) missiles would thus probably increase strategic stability in the region without necessarily being a complete game-changer.
  • However, for that increase in stability to happen, two conditions would have to be met:
    • All three major Asian nuclear powers would need to have them; in the meantime, access to strategic submarines by one or two (but not three) could be more destabilising than stabilising.
    • Maritime nuclear forces would need to be protected from attack either through continuous at sea deterrence (CASD) or through heavy natural protection (such as the Hainan island base); otherwise, they could become tempting targets, with the risk of adding more instability than stability. This also implies an investment in nuclear force protection (anti-submarine warfare frigates, maritime patrol aircraft etc) to ensure that a ship leaving for patrol does not become an easy target; any investment in a sea-based nuclear capability implies an additional investment in non-nuclear forces.


  • These two conditions are unlikely to be fulfilled anytime soon, and the peculiarities of the Asian maritime theatre (access to oceans, nature of the waters) will make them harder to achieve than in the East-West context. This is another reason why, for operational patrols, 'bastion' practices will be more tempting than 'dilution' ones.
  • Because of command and control challenges, countries which combine assertive nuclear control cultures and de-mating practices (China and India) will not naturally be inclined to allow for operational patrols of submarines. In other words, CASD will not come easily to Asia.
  • That said, access to modern submarine-based secure second-strike capabilities might be faster, relatively speaking, than it was in the East-West context, due to technological developments that will make some key capabilities (accoustic discretion, secure communications, etc) easier to achieve than was the case in the 20st century.
  • It is hard to argue that theatre nuclear weapons at sea (for use against other maritime forces) would increase strategic stability in the region. They may lower the nuclear threshold in a conflict.
  • Finally, an inescapable feature of the Asian nuclear landscape is its multilateral nature (four nuclear countries in the region plus Russia and the US). Three independent Asian nuclear actors plan to put part of their nuclear weapons at sea, and since the beginning of this discussion, it has been learned that the fourth (North Korea) may also have plans in this regard. This 'built-in complexity' of the Asian nuclear scene may be more important, at the end of the day, than the structure of the respective arsenals of the countries concerned.

 The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Cyberwar and war in space: Making SSBNs more dangerous

Published 29 Sep 2014 08:37   0 Comments

As several participants in our debate have argued, nuclear ballistic missile submarines (SSBN) can have a positive effect on strategic stability in Asia and globally. But they do not exist in a vacuum. New military capabilities, and strategies that take advantage of them, are being developed and deployed in the Indo-Pacific that make the gradual proliferation of sea-based nuclear weapons dangerous rather than stabilising. 

These novel weapons, such as cyber and electronic warfare, anti-satellite missiles and hypersonic technology, add new dimensions to both conventional warfare and nuclear deterrence. Their development, along with their roles in comprehensive strategies, such as the US’s Air-Sea Battle concept, requires us to ask whether the introduction of Chinese and Indian sea-launched nuclear weapons will only create instability and the risk of escalation in conflict. 

The role of SSBNs is to provide an assured second-strike capability to a nation's nuclear deterrence. Essentially, a second strike capability acts as a kind of fail-safe by ensuring that any aggressor takes on the risk of being attacked by nuclear weapons in-kind. Thus, theoretically, SSBNs and assured second strike should lead to a more stable strategic system in the Indo-Pacific by deterring any potential disabling first strike. [fold]

As Rod Lyon has argued, the SSBN can make an aggressor think twice, as long as the threat of the platform is credible. It is mobile, quiet and difficult to track. Once professional crews, reliable communication technology and effective command and control are established, the SSBN can act as a credible deterrent. But if the SSBN is to play a positive role in strategic stability, communication with state leadership must be guaranteed. 

Communications with submerged submarines, both conventional and nuclear, are established through very low frequency and extremely low frequency programs. These involve large antenna installations that are part of a state's military communications network. Thus for example India, conducting sea-trials of its first SSBN, has started construction of its own very low frequency station

But what happens to deterrence and stability if such communications come under attack?

In the Cold War, the main way to neutralize an adversary's submarine-launched nuclear weapons was through anti-submarine warfare; detecting and tracking enemy SSBNs and, in the event of war, destroying them before they launched. 

There was, of course, the risk that during a conflict anti-submarine warfare could induce 'use it or lose it' decisions on a state's leadership. That destabilising factor is now amplified by another possibility raised by new technologies: the prospect that a state's communications with its nuclear deterrent force could be cut in times of crisis.

What would happen in a future conflict in which the opening attack involved the use of cyber and other capabilities to disrupt or destroy military communication systems? How could we be certain that SSBN commanders, cut off from political authority, would not launch their weapons? 

This goes to wider questions about vulnerability of communications, including satellites, in conflict. The head of US Air Force Space Command recently said that if one of the Advanced Extremely High Frequency satellites, a backbone of US military communication, was taken out 'we could potentially have a situation where the president can't communicate with forces in that part of the world.'

There is no guarantee that striking another power blind or dumb in the midst of crisis would add to stability. Thus the US Air-Sea Battle concept has an uneasy relationship with nuclear deterrence. Designed to counter Chinese anti-access and area-denial capabilities, Air-Sea Battle requires the integration of all 'interdependent warfighting domains (air, maritime, land, space and cyberspace)' in order to 'disrupt, destroy and defeat' enemy forces. The strategy calls for the disruption of enemy 'command, control, communication, computers, intelligence, surveillance and reconnaissance' systems before attacking their weapon systems and capabilities.

Many of these communication systems, like the low frequency installation India is building, are dual-use in the sense that they could network with conventional and nuclear forces. Thus it is possible to foresee a situation where a 'blinding' campaign like that envisioned in Air-Sea Battle could involve attacks on an installation that also communicates with SSBNs, radically disrupting a state's control over its sea-based nuclear arsenal. Presumably, India would face a similar problem if Pakistan or China ever planned to target its communications at the outset of a conflict.

These are some of the complexities and scenarios that will need to be thought through if the introduction of Chinese and Indian nuclear-armed submarines is to reduce risks of conflict rather than heighten them.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Photo courtesy of Flickr user U.S. Navy Official Page

Sea-based nuclear-weapons: Military needs and political consequences

Published 12 Sep 2014 15:18   0 Comments

How will the deployment of ballistic missile submarines by China and India affect the Indo-Pacific strategic landscape? What effect will these deployments have on stability in the region? 

Unsurprisingly, the contributions thus far have shown that the picture is, as Rory Medcalf put it, 'murky.' As Bruno Tertrais pointed out, much of the inmpact on stability from these deployments will depend on the quality of the submarines, the range and reliability of their accompanying missiles, and the skill of their crews, as well as on the anti-submarine warfare efforts of their prospective foes. At the same time, as Tom Mahnken noted, a greater sense of second-strike assurance may embolden rather than relax at least China's ambitions. Meanwhile, Rod Lyon has observed that, even with all the qualifiers, strategic submarines tend to make adversary decision-makers think twice about attempting a first strike.

Thus far, the debate seems to be clustering around a general view that the deployment of ballistic missile submarines (SSBNs) is neither a panacea nor a catastrophe for stability, and that much will turn on how they are operated and on how much they are relied on for strategic advantage. 

One aspect of their deployment that has not been sufficiently remarked upon, however, is how the deployment of systems as strategically significant as ballistic missile submarines may influence regional naval doctrine and operating patterns, and even national strategic objectives more broadly. Lyon touched on this point when he wrote that 'even vulnerable SSBNs might have value if deployed in protected bastions, behind layered defensive screens, exploiting known seabed topographies, confusing the targeteer with diversionary noisemakers, and keeping the warhead loadings low per boat.'

The broader point is that effective deployment of a ballistic missile force is not simply about getting a boat into the water with operational missiles loaded. [fold]

Rather, attaining more than a bare bones second-strike capability at sea means ensuring those submarines are survivable, can communicate reliably with national leadership, and that their missiles can reach their assigned targets. This is by no means an easy task for a country like China when one faces a highly capable potential adversary like the US Navy, not to mention the Japanese Maritime Self Defense Force, the Royal Australian Navy, and others. 

Accordingly, if China is really serious about achieving an assured second strike capability with its ballistic missiles submarines – by no means an unreasonable supposition, given the cost and scale of the effort – it will need to ensure that these submarines can meet the criteria laid out above. This might be done, as Lyon indicated, by developing sufficiently quiet submarines. We can presume the PLA Navy is working at that assiduously. But will they be sufficiently confident that their submarines are quiet enough to survive, and to survive for long enough? If not, the Chinese may look to other means of protecting their submarines, means that could have considerable strategic consequences. 

Let's look backwards to give some context. As Owen Cote has related, in the 1960s and early 1970s, the Soviet Union deployed its early cruise missile and ballistic missile submarines forward, into the Atlantic. Starting in the mid-1970s, however, the Soviets, alerted to the vulnerability of their submarines by the Walker spy ring, began shifting to a 'bastion' strategy in waters nearer to the USSR, protecting the valuable missile submarines from the US Navy's anti-submarine warfare (ASW) capabilities with layers of defences including air cover, surface ships, and so forth. This entailed a major shift in the doctrine and operating patterns of the Soviet Navy that changed the 'waterprint' of its naval forces. Protecting their boomers, in other words, drove major changes in how the Soviets operated their naval forces, in this case back from forward positions to zones closer to the homeland. 

If China were also concerned about the vulnerability of its missile submarines to the ASW capabilities of the US and its allies, it too might seek 'bastions' and/or other means of protecting these submarines. These efforts at protection could include establishing a higher military presence and even attaining greater control over airspace above the seas in which the PLA Navy would want to operate its submarines. This in turn would mean that Chinese forces might operate and train in seas and airspace that had not traditionally seen much PLA presence and at considerably higher tempos and in a more sophisticated fashion than in the past. China might even seek to obtain formal or informal control or operational dominance over certain seas and airspace – either through gentle means or through coercion – to ensure the security of its missile submarines. 

Such efforts would, of course, have significant political ramifications. But it would hardly be the first time military requirements had helped form political objectives. US requirements for bases during the Cold War drove much of Washington's alliance policy, particularly outside of Europe. And a good bit of Britain's policy in its imperial heyday was motivated by the need for coaling and refitting stations. 

This point should not be carried too far. China is sensitive to political constraints on the exercise of its military power, and we can assume that part of the appeal of SSBNs for Beijing is that they hold out the promise of being able to operate independently and without much fuss. 

Still, in thinking about the implications of China's ballistic missile submarines on stability, we should not ignore that the demands of survivability and operational effectiveness could also entail considerably broader military operational and ultimately political consequences. Much will depend on how much China values these submarines, how quiet it believes them to be, the effectiveness of US and allied ASW efforts, the intensity of rivalry in East Asia, and a range of other factors.

But the point is that the effort to deploy a genuinely survivable and effective ballistic missile submarine force could have consequences well beyond the narrow concerns of submarine quality, crew skill, and missile range.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Photo by Flickr user UK Ministry of Defence.

Sea-basing threatens India's minimalist nuclear strategy

Published 1 Sep 2014 09:45   0 Comments

Both the draft nuclear doctrine released in 1999 and the official nuclear doctrine released later in 2003 state India's commitment to a minimalist nuclear posture.

This nuclear minimalism was best advocated in the policy of credible minimum deterrence (CMD). Two assumptions inform the concept of CMD. First, that deterrence can be projected at low numbers, and second, that a ready arsenal – delivery vehicles mated with warheads at continuous alert – is unnecessary. The commitment to low numbers of warheads meant that CMD could help avoid unnecessary 'vertical proliferation'. Such a posture was therefore considered propitious for nuclear stability.

But will CMD remain valid as India shifts its nuclear arsenal to the sea? The coming of the Arihant, India's first nuclear-powered and nuclear-armed ballistic missile submarine (SSBN), constitutes a formidable challenge to India's posture of credible minimum deterrence and therefore, also to strategic stability in the region.

The present configuration of INS Arihant allows it to carry 16 nuclear-tipped missiles. By the end of this decade, India plans to deploy five to six such SSBNs. Clearly, the warheads required to arm these submarines would alone be close to the current estimates of the total number of nuclear weapons (between 90-110) in India's arsenal. This increase in numbers would not be alarming if India was to shift its entire nuclear arsenal underwater as France and Britain have done. In fact, in 2000, in a well argued and equally well received book on India's nuclear strategy, Raja Menon – an influential strategic analyst and a retired rear admiral – suggested precisely this course.

Various factors militate against such a prospect, however. [fold]

For one thing, the current generation of India's sea-launched ballistic missiles lack the range for an underwater deterrent to be credible. The K-15 or Sagarika, the only missile ready to be deployed on Arihant, has an effective range of only 700km. Though this may be sufficient for projecting second-strike capability against Pakistan, it is clearly inadequate for retaliating against China. With such a short range, Indian SSBNs would have to enter dangerous waters in East Asia to release their payloads. India, therefore, will continue to rely on aircraft and missiles for nuclear delivery. The rivalry among India's army, navy and air force will also frustrate any shift to an underwater-only nuclear arsenal. All three services want a part of the nuclear arsenal, both for budgets and prestige. This is similar to the US experience during the initial years of the Cold War.

Furthermore, the number of Indian nuclear warheads would spike if the Defence Research and Development Organisation's (DRDO) ambitious plan of introducing multiple independent re-entry vehicles (MIRV) into India's nuclear delivery systems bear fruit. The DRDO claims that, in the near future, Indian missiles could be capable of carrying 4 to 12 nuclear warheads atop a single missile. Multiple warheads clearly imply a multiplying arsenal. 

Then there is the question of India's nuclear readiness. The conventional wisdom is that India's nuclear weapons are in a state of 'recessed deterrence' – disassembled, de-mated and de-alerted. In case of a nuclear emergency, operationalising the nuclear arsenal would require coordination among multiple agencies such as the DRDO, the Atomic Energy Commission (AEC) and the armed forces. All these agencies control different subsystem of the nuclear arsenal: AEC controls the nuclear core; DRDO controls the non-fissile triggers and the armed forces control the delivery vehicles. Such diffusion automatically suggests a disassembled arsenal.

However, as Vipin Narang has argued recently, the idea that 'India keeps its nuclear weapons is a disassembled largely now just a myth'. DRDO has publicly articulated its position of 'canisterising' or 'encapsulating' all nuclear delivery systems, which requires that a 'warhead is likely to be pre-mated to the delivery vehicle and kept hermetically sealed for storage and transport'. The rationale emanates from the need for a credible second strike capability. As the DRDO chief explains, 'In the second strike capability, the most important thing is how fast we can react.  We are working on cannisterised systems that can launch from anywhere at anytime'.

Though last-minute checks and balances would still be in place, this is not a picture of a 'disassembled' nuclear force. This is particularly true of nuclear-armed submarines. Since such submarines may have no links with the mainland during a patrol, warheads cannot be possibly detached from the delivery vehicles. In the case of land-based and air-based delivery platforms, coordination among multiple agencies is still possible, but an underwater deterrent requires a ready arsenal. 

So Arihant and its progenies will not only increase the size of India's nuclear arsenal but also its readiness, making the idea of a CMD practically meaningless. This could have a spiral effect on Pakistan, which would increase its own weapons production and battle readiness. We are already witnessing this, with increasing numbers in her nuclear arsenal and intentions to develop tactical nuclear weapons. It may also lead to new proliferation challenges for India if Pakistan avails of China's services to acquire its own nuclear triad.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Image courtesy of Wikipedia.

Why Indian and Pakistani sea-based nukes are so troubling

Published 29 Aug 2014 14:07   0 Comments

The danger of sea-based nuclear weapons in Asia depends on the strategic context of the potential protagonists, along with the particulars of the platforms, delivery system, and doctrines.

Perhaps the least menacing in the short term is the interaction between India and China as each builds its sea-based nuclear capability. There are still years to go before each state has systems coupled with the need to deploy them in locations that could lead to dangerous interactions.

A second dyad, between US sea-based nuclear weapons and the growing Chinese maritime nuclear arsenal, has the potential for misunderstanding, risk-taking, and escalation, but Washington and Beijing are not in a state of on-again, off-again militarised hostilities. This, coupled with the distance from China that US nuclear-armed ballistic missile submarines are likely patrol, limits some potentially dangerous interactions.

The India-Pakistan dyad, however, carries the potential to be the most menacing in the short-to-medium term.

Both India and Pakistan are at the initial stages of deploying nuclear weapons on submarines. Being new to a deployed technology and operational technique does not mean the two governments and their militaries will not be careful or capable. Both states are likely to be highly cautious and professional in their deployment of these capabilities. However, there is always a learning curve with new capabilities and therefore always chances for misperception, miscalculation, and the threat of escalation.

Three additional factors in the South Asian context make this newly emerging set of capabilities particularly troubling. [fold]

The first is the very short range of India's first generation submarine-launched ballistic missile (the K-15 has a reported range of 750km) and Pakistan's likely submarine-launched cruise missile (the Babur, with a reported range of 700km). The second is that it appears Pakistan will be deploying its sea-based nuclear capability in a dual-use platform, a diesel-powered attack submarine. Finally, the two states have a history of wars and militarised crises over a range of disputes that will not be resolved anytime soon. 

Unlike the deployment of nuclear warheads on land-based missiles or nuclear gravity bombs, sea-basing of nuclear weapons carries a much greater chance of close-up and regular interaction between the forces of two potential protagonists. In peacetime, once India and Pakistan actually have operational platforms deployed, it can be expected that each side will seek to gather intelligence on the acoustic signature of the other side's submarines, along with information about operating patterns and locations. This creates chances for accidents, incidents, or heightened tensions, particularly as the relatively short ranges of the missiles mean that deployment areas may be relatively close to the other's territorial waters.

Yes, such submarine-versus-submarine interactions occur already without any public acknowledgment of increased tensions, but the importance of nuclear weapons may cause both sides to take greater risks both to gather intelligence and to defend a nuclear-armed platform. Similarly, both sides may become more aggressive in patrolling and defending territorial waters, contiguous zones, and even exclusive economic zones if they want to deny the other side from gaining operational familiarity with a particular stretch of water.

If another militarised crisis between India and Pakistan were to occur after the deployment of sea-based nuclear weapons, the chances of inadvertent escalation will be higher than in an environment absent these platforms. In the case of Pakistan's likely nuclear platform – an Agosta-class submarine basically indistinguishable from its conventionally-armed counterpart – Indian naval commanders and their civilian leadership may be faced with a difficult dilemma. Protecting India's surface and submarine fleet from Pakistan's submarines in a crisis or war requires aggressive detection measures and attacking potential contacts. However, India may feel constrained if it does not want to inadvertently escalate a crisis or conflict by destroying the 'secure second-strike' portion of Pakistan's nuclear triad. If India were to destroy a Pakistani submarine carrying nuclear-armed missiles as part of a conventional war, would Pakistan's leadership interpret this action as crossing a nuclear threshold?

Similarly, in a future crisis or conventional war, what would Pakistan do to place itself in a better position to track and, if possible, destroy the INS Arihant or its successors? Pakistan has shown itself both willing and able, as far back as 1971, to undertake long-range, risky submarine operations in an attempt to strike at high-value Indian assets on India's east coast. Would India view such a Pakistani operation in a future crisis as escalatory? What would its response be?

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia

Strategic stability and Chinese SSBNs: The need for net assessment

Published 28 Aug 2014 12:05   0 Comments

In his introduction to this Interpreter debate, Rory Medcalf raises the important question of how nuclear-armed ballistic-missile submarine (SSBN) programs in Asia influence strategic stability.

Making such an assessment for any one weapons system in isolation is fraught with difficulty, as judgments are inevitably based on assumptions about doctrine, employment, escalation, and strategic concepts. Technical details also matter a lot, as was demonstrated in the late Cold War by the development of the highly precise Trident D5 (which gave the US SSBN fleet the ability to conduct counterforce missions against hardened targets) on the one hand, and the appearance of very quiet Soviet submarines (pictured) on the other. Strategic stability is thus always a question of net assessment.

Viewed in this light, the scale and scope of the programs under development in Asia today seem unlikely to change fundamental power relationships and military balances. India and China have toyed with SSBN technology for decades, and it is difficult to see either action-reaction patterns, or an out-of-character acceleration, that would indicate an incipient SSBN arms race. That said, the fact that SSBNs are now being introduced into the regional mix of capabilities throws a useful spotlight on the influence of geography, and on Chinese views about the vulnerability of their nuclear forces. Both of these factors are of fundamental importance to net-assessment-based judgments of strategic stability in the Western Pacific, and highlight the strengths of the current strategic order that China must still overcome.

The attraction of SSBNs is that they can be difficult to find and destroy, particularly if they are either isolated from adversary ASW forces in a 'bastion' or able to hide in the vast expanses of deep water found in the Pacific, Atlantic, and under the Arctic ice cap. Strategic geography thus favoured the employment of SSBNs by the main nuclear powers of the Cold War (the US, Soviet Union, France and Britain), whose submarine bases had direct access to suitable deployment areas.

Not so in China's case. While the waters of the northern South China Sea are deep, they are also confined. [fold]

The need to pass through chokepoints into the Pacific places Chinese submarines at a disadvantage, as it makes it easier to for US and allied ASW forces to detect and track Chinese SSBN patrols passing into the Pacific, or to block them through mining in wartime. Moreover, the South China Sea is ringed by US allies, and any 'bastion' the PLA Navy might attempt to establish could be contested by a range of US and allied systems operating from friendly territory. Those systems would of course themselves be at risk of Chinese attack, but the heart of a conventional battle would not be a good place for an SSBN to be.

'Deploying' the SSBN in the cave complex on Hainan Island might align more closely with the Chinese preference to keep close control of nuclear warheads, but it would significantly limit the strategic benefit of having an SSBN capability: if they remain inside the caves too long, the Chinese SSBN force risks being disabled by a US strike (even if this required nuclear weapons). Should they leave the caves in a crisis, however, China risks sending inadvertent escalatory signals, and the boats would enter waters likely to be teeming with US attack submarines.

All of this raises the question of why China is developing SSBNs in the first place. The reasons are far from clear, and a coherent strategic rationale may not even exist in Chinese minds. SSBN development is consistent with the long-term features of Chinese nuclear strategy and force modernisation, which emphasise survivability through dispersion of its land-based systems. With the DF-31 and DF-31A, China can now retire its only silo-based system, the large DF-5 ICBM, and rely completely on solid-fuel, road mobile nuclear missiles.

And yet the development of an SSBN force indicates that China is not fully confident in the survivability of its land-based nuclear forces, and is at least hedging its bets. This is not fully unjustified, as land-based missiles still have to operate in prepared deployment areas that are vulnerable to the large-scale nuclear suppression campaign, of which the US is still capable. US attempts to build a survivable launcher for its own land-mobile Midgetman missiles during the Cold War are a salutary reminder of the inherent fragility of mobile ICBMs to nuclear blast pressure. Adding SSBNs to the mix would certainly complicate US planning for the unlikely event that it should ever consider a disarming strike on China, but it does not change the basic source of China's vulnerability, which lies in the numerical imbalance of the nuclear forces of both countries.

Investment in SSBNs thus indicates that China remains uncomfortable with the limits imposed by its small nuclear arsenal. But the scale of China's investment doesn't really address the issue. SSBNs put a lot of eggs into one basket and are no panacea for the problem of survivability, especially given China's geographic disadvantage. As such, their appearance in the region is a useful reminder that the broader factors underpinning strategic stability in the region — US military capabilities, including its nuclear arsenal, and the alliances they support in the Asian littoral — have a lot going for them still.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia

Sea-based nukes: A marginal effect on stability

Published 27 Aug 2014 13:47   0 Comments

There are several sources of instability in the Asia Pacific region today. Some are political, such as China's pursuit of territorial claims at sea and on land at the expense of its neighbours. Others are military, such as those elements of Chinese military modernisation aimed at coercing Beijing's neighbours and countering US extended deterrence guarantees and power projection capabilities. Chinese doctrine also contains features that could be highly destabilising. Finally, there is a considerable potential for misperception among actors in the region.

The deployment of nuclear-armed submarines (SSBNs) is unlikely to contribute greatly to stability, but neither is it likely to create instability where none existed or to magnify existing sources of instability.

Beijing is undertaking a large-scale modernisation of its military, including its nuclear force. According to Department of Defense and press sources, China is fielding the mobile DF-31A intercontinental ballistic missile and is developing the mobile DF-41 with multiple independently-targetable re-entry vehicles. According to press reports, China has also conducted at least two tests of the WU-14 hypersonic boost-glide vehicle. China also fields theatre nuclear strike systems such as the DF-21. And China has invested considerable resources in developing and deploying the Jin-class SSBN and JL-2 submarine launched ballistic missile (pictured).

China's nuclear modernisation is aimed at giving the Chinese leadership a secure second-strike capability. As Tom Christensen has argued, that is in turn likely to embolden China (if it has not already done so) to pursue a more aggressive foreign policy. The deployment of SSBNs is clearly part of that but is far less consequential than other Chinese developments. These include:

  • The continuing deployment of large numbers of precision conventional ballistic missiles that threaten China's neighbours.
  • The fact that China apparently to some extent co-mingles the deployment and command and control of its nuclear and conventional forces.
  • The Chinese Second Artillery Force's doctrine, which discusses missile strikes in close proximity to hostile forces as deterrent actions.

Misperception and miscalculation are always a possibility with the deployment and operation of any new capability, and it would behove the Chinese Government to be transparent in its plans for its SSBN force. That said, the deployment of SSBNs is likely to be far less consequential than other elements of Chinese military modernisation.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Photo courtesy of Sinodefence Forum.

Nuclear weapons and Pakistan's naval strategy

Published 22 Aug 2014 07:43   0 Comments

Since 1998, when India and Pakistan both burst out of the nuclear closet and publicly revealed their formerly recessed nuclear capabilities to the world, scant commentary has been made on the impact that the introduction of sea-based delivery systems would have on the South Asian nuclear equation.

This can be attributed, in part, to the relatively recent nature of naval nuclearisation in South Asia. India launched its first indigenously produced nuclear submarine, the INS Arihant, in 2009, and Pakistan only formalised its ambitions for a functional nuclear triad (via an Inter Services Public press release) in May 2012. However, while public discussions in both countries on complex issues such as nuclear naval strategy still remain somewhat inchoate and have yet to fully mature, India's nuclear submarine program was, in fact, initiated over three decades ago. Furthermore, there are statements by Pakistani leaders and naval commanders referring to the need for Pakistan to acquire a nuclear triad that long precede India's public unveiling of the Arihant.

It is important, first of all, to emphasise that both countries have their own distinct sets of motivations to engage in naval nuclearisation.

All too often outside observers almost mechanically hyphenate the two South Asian nations and reduce the multi-layered complexity of their nuclear interactions to a simple action-reaction dynamic. India, for example, is motivated in part by a desire for prestige and international recognition, but also by a very rational objective to place its nuclear assets at a safer distance from a decapitation strike. This is particularly important in light of China's growing militarisation of the Tibetan plateau and the proliferation of Chinese ballistic-missile silos in strategic high-altitude points along the border. In addition, there are mounting concerns over the reach of Chinese air power, Chinese advances in electronic and cyber warfare, as well as over recent reports that indicate China is developing a navalised variant of its 3000km-range Dong Hai 10 cruise missile.

Pakistan has its own strategic rationale for developing a naval nuclear capability which is at least partly independent of a simple desire to mirror India's advances. But the point that bears most emphasis here is that through its threats to disperse nuclear assets among various components of its fleet, Pakistan can offset India's increasingly overbearing conventional naval advantage in the Indian Ocean. When interviewed, Pakistani commanders mention the precedent set by Israel's alleged decision to place nuclear-tipped cruise missiles aboard conventional submarines and have suggested to me, somewhat provocatively, that Pakistan should follow suit. [fold]

Another option, some have argued, would be to station nuclear weaponry aboard surface ships and maritime-patrol aircraft. Not only would this provide the country with greater strategic depth, it would also extend some of the more dysfunctional elements of Indo-Pakistani nuclear interactions from land to sea. By threatening, either directly or indirectly, to employ low-yield nuclear weapons at sea, or against an advancing Indian aircraft carrier strike force, Islamabad can hope to acquire 'escalation dominance' and thus considerably dilute its larger neighbour's coercive naval power, much in the same way that it has managed to dilute India's conventional advantage on land.

In both cases, this has been achieved by a refusal to abide by a No First Use (NFU) policy and, increasingly, through a flirtation with the tactical use of nuclear weapons as warfighting instruments. This has been achieved, in part, through shifting from an earlier generation of enriched uranium nuclear weapons to a newer generation of plutonium weapons, allowing Pakistan to significantly expand its nuclear arsenal (which now appears to have overtaken India's nuclear weapon inventory) and to make progress in the miniaturisation of its nuclear warheads for battlefield use.

To provide a concrete example, most analysts now concur that Pakistan is developing a sea-based version of its Babur missile, a subsonic nuclear-capable missile that bears an uncanny resemblance to the US Tomahawk, albeit with a much shorter range.

The introduction of nuclear weapons will have a major impact on the future of naval warfighting in the Indian Ocean. Fleets caught under a nuclear shadow are compelled to operate under different principles. Most notably, ships must loosen their deployment patterns and adopt more dispersed configurations to better shield themselves from the ripple effects of a nuclear blast. For Pakistani security managers, acquiring nuclear-armed cruise missile submarines could provide an opportunity to skew the existing naval power dynamic, primarily by injecting an even greater degree of uncertainty and ambiguity in India's tactical calculus, but also by preventing the Indian Navy from concentrating the bulk of its power projection platforms in one location.

Such a toxic combination of dual-use platforms and doctrinal opacity could prove highly detrimental for crisis stability. In the event of conflict, there would be no way for India to ascertain whether Pakistani vessels or maritime patrol aircraft are nuclear-armed or not, and a radioactive 'fog of war' would float over combat operations.

A common reading of the movement towards sea-based deterrence is that it provides a greater vector for strategic stability, not only by ensuring the relative sanctuarisation of nation's deterrents and thus reducing first-strike incentives on both sides, but also by displacing the locus of nuclear competition from heavily populated state territories to the wide open waters. This optimistic vision does not hold up to scrutiny, however, when applied to regional nuclear dynamics in the Second Nuclear Age. Indeed, in this particular case, one could argue that it is not so much the process of naval nuclearisation itself which is inherently stabilising or destabilising, but rather the manner in which it is being pursued. Pakistan seems to be taking a dangerous path which combines dual-use systems (nuclear-tipped cruise missiles), cultivated doctrinal ambiguity, and a fair degree of maritime brinkmanship.

There are, no doubt, numerous lessons that could be drawn from the Cold War, whose study unfortunately tends to be neglected or oversimplified in South Asia. During the second half of the Cold War, in particular, theorists warned that within a heavily nuclearised environment, and under conditions of strategic uncertainty, offensive submarine operations or deployments could give birth to dangerously escalatory dynamics. And interestingly, much as in contemporary Pakistan, this argument was countered at the time by a constituency that argued that the diversification — and resulting dispersal — of nuclear assets at sea both strengthened their survivability and buttressed overall deterrence.

For instance, Linton Brooks, who served on the Reagan Administration's National Security Staff, wrote in 1986 that:

Deterrence is enhanced through the deliberate importation of both risk and uncertainty...Sea-based systems, able to attack a wide spectrum of targets from a large number of platforms, over a broad spectrum of attack azimuths, complicate Soviet defense planning immeasurably, thus strengthening deterrence.

Depressingly, however, things may in fact be even more complex and unstable now, in large part because the South Asian maritime environment is so alarmingly unstructured. At least during the second half of the Cold War (from 1972 onwards) the Soviets and Americans enacted the INCSEA, which worked towards limiting critical misinterpretations in times of tension. India and Pakistan have no such regime in place, and Pakistan continues to rely on a policy of maritime brinkmanship to compensate for its conventional inferiority.

There are frequent reports, for instance, of near collisions between Pakistani and Indian surface vessels. And in 1999, a Pakistani maritime patrol aircraft was shot down by an Indian Mig-21 when it strayed into Indian airspace. If Pakistani frigates or maritime patrol aircraft were transporting nuclear weapons and such incidents were to reoccur, the implications could be severe.

The scattering of nuclear assets at sea, particularly aboard surface ships, also heightens the risks of a nuclear weapon being intercepted by a malevolent non-state actor, a perennial concern when discussing Pakistan's growing nuclear arsenal. Another question worth raising is whether the escalation dynamics of nuclear warfare in the maritime theatre are less constrained than those that would attend similar operations on land.

A classic example is the tense situation which unfolded underwater during the Cuban Missile Crisis and which almost led to disaster. We now know that each of the Soviet submarines deployed off Cuba was in fact armed with nuclear-tipped torpedoes, a fact which was not known by the US Navy at the time. In an attempt to force the Soviet submarines to surface, the US fleet dropped depth charges which were not intended to hit the submarines but rather to coerce them into revealing themselves. The Soviet submarine commanders, however, viewed these actions under a different light, and one harried commander even ordered his men to assemble the nuclear torpedo to battle-readiness.

This incident highlights two disturbing dimensions of naval nuclear interactions: the perennial risks linked to misperception and ill-conceived or designed signaling, and the various challenges linked to command and control. When it comes to contemporary South Asia, even though Pakistan has threatened to use tactical nuclear weapons against advancing Indian tank formations on land, one could be forgiven for expressing severe reservations over whether Pakistani commanders would be willing to detonate nuclear weapons on their own soil. Out on the open waters, however, such a question remains uncomfortably open.

Finally, analysts will now need to pay much closer attention to the interaction between conventional and nuclear assets at sea, and how this will impact on each country's strategies, doctrines, and acquisitions. Technology, like geography, can blur the line between defence and offense. For example, whereas previously the question of submarine proliferation in South Asia could be viewed through a purely conventional prism, everything will become a lot more complicated now that nuclear-armed and nuclear-powered assets have been thrown into the mix. Formerly conventional naval warfare capabilities such as anti-ship warfare or anti-submarine warfare can now also be equated with counterforce capabilities, with all the destabilising ramifications such a conceptual shift implies.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Photo by Flickr user Kashif Mardani.

INS Arihant revealed

Published 21 Aug 2014 15:55   0 Comments

As we begin the second round of our debate on sea-based nuclear weapons in the Indo-Pacific, here is the first clear image of the INS Arihant, India's first indigenous nuclear-powered submarine, to be armed with either a dozen 750km-range nuclear tipped ballistic missiles or four larger missiles with 3500km range. The image above is a still from a news report by India's NDTV, which broke the story yesterday.

An earlier image gave very little away, whereas in this shot we can clearly see the distinctive 'hump' aft of the sail, where the ballistic missiles will be housed. I'm no naval architect, but the sail looks to be of a rather dated design, reminiscent of the Soviet-era Kilo-class submarines the Indian Navy already operates. That's not too surprising, since Arihant has been in development since 1998. On the other hand, the designers seem to have done a much better job of integrating the missile hump with the hull than has China with its Type 094.

As our debate on sea-based nuclear weapons has already shown, the performance of the submarine is critical for strategic stability in the region. If the ship is noisy and easy to track, it will not give India the guaranteed second-strike capability it wants in order to dissuade an adversary from mounting a surprise attack. And of the ship is armed only with relatively short-range weapons such as the 750km K-15 missile, it would need to operate dangerously close to an adversary's home waters, thus making the ship vulnerable and destabilising. The longer-range K-4 missile has been tested from an undersea platform but is years from being operationally deployed on Arihant and her eventual sister-ships.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Even noisy submarines can be stabilising

Published 21 Aug 2014 14:36   0 Comments

Having read the initial round of contributions to this debate, I must say I'm not a believer in the idea that sea-based nuclear weapons are destabilising. In large part, that's because I'm finding it difficult to construct a scenario in which a senior defence adviser ever uses the sentence, 'Mr President, we have to attack now, they have sea-based nuclear weapons.' True, the future is an unwritten page so it's impossible to say with certainty that such a sentence will never be uttered. But on any rational calculation of probabilities, I know which way I would bet.

Does that mean we can look with equanimity at the forthcoming deployment of nuclear weapons at sea by Asian nuclear powers? Well, not entirely. It's true that some force structures are more destabilising than others. In particular, deployment of vulnerable high-value targets doesn't contribute to good crisis stability. So if Asian powers were to deploy large warhead numbers in vulnerable, noisy SSBNs, they'd have to anticipate losing at least some of those boats early in a conflict. Still, even vulnerable SSBNs might have value if deployed in protected bastions, behind layered defensive screens, exploiting known seabed topographies, confusing the targeteer with diversionary noisemakers, and keeping the warhead loadings low per boat. Quiet SSBNs would have value without that supporting architecture.

Deployment of nuclear weapons at sea doesn't guarantee invulnerability. But the development should typically be seen as positive in relation to Asia's current monopedal force structures. No Asian power has a strong 'air-breathing' strategic leg. They're mainly just land-based forces. Having a sea-based leg is something of a safeguard against technological surprise. [fold]

Moreover, I think there are important political gains to be derived from sea-based systems, and those might be more important than the strategic and technological ones. First, such systems suggest a commitment to a durable, resilient nuclear force. They suggest that resort to nuclear weapons needn't be — and won't be — a rushed decision. Second, they devalue the benefits to an adversary of a bolt-from-the-blue attack upon the land-based component of the force, usually sited in relatively static target sets. Third, because they make such an attack upon the land-based systems less likely, they help reassure the population of the nuclear weapon state that they aren't mere nuclear cannon fodder, and thus help sustain political support for the arsenal.

Finally, I'd make one simple observation: if Asia's nuclear-armed countries want to build and deploy sea-based nuclear weapons, who's going to stop them? Nations typically have the right to get their own defence procurement decisions wrong. And in this case it's far from evident that decisions to deploy nuclear weapons at sea would be wrong.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Photo by Wikipedia.

SSBNs destablising? Not if command and control is maintained

Published 12 Aug 2014 09:42   0 Comments

Ballistic missile submarines (SSBNs) became the seagoing platform of choice for the deployment of strategic nuclear weapons by 1960, with the availability of submarine-launched ballistic missiles. Today there are five countries with operational SSBNs. The US, the UK, France and Russia all have a major part of their deterrent capability deployed on SSBNs, while China has three or four SSBNs, though not all are operationally available.

Before getting into a discussion on how the spread of sea-based nuclear weapons in Asia would affect stability, it is worth revisiting some concepts regarding 'stability'. To clarify, this discussion is about nuclear stability, not about prevention of conventional conflict. In other words, our frame of reference is to examine whether the possession and deployment of nuclear-armed submarines in Asia would provoke, or conversely prevent, escalation of a conflict over the nuclear threshold. With this in mind, the following is a brief review of the existing concepts:

  1. Strategic stability exists when there is mutual acceptance of relative nuclear force levels (which is not the same thing as the forces being equal) and neither side has the intent or desire to alter it. A change in this relativity could induce willingness to strike first, either by the side that perceives itself as weaker (as a pre-emptive defensive measure) or by the side that sees itself as stronger and therefore immune from effective counterstrike.
  2. Crisis stability exists when the nuclear weapons of both sides are not vulnerable to inadvertent or unauthorised launch, when both sides are confident in each other's determination to avoid escalation, and when the command and control (both politico-military as well as technical) is robust and can withstand political crises.
  3. Deterrence stability prevails when each side knows that the nuclear forces of the other will survive an attack and be able to deliver an effective retaliatory strike with consequences that will be unacceptable to it. 

The only Asian country that currently has SSBNs in service is China, though their detailed operational status is not clear. India is in the process of operationalising its first SSBN; however it is not clear when a matching submarine-launched ballistic missile (SLBM) will be available. Pakistan does not have any SSBNs and has not declared any intention of building or acquiring any, though there are reports of it considering nuclear warheads for its submarine-launched cruise missiles. The only other nuclear weapons deployed in the Asian maritime region are those on US and Russian submarines. With this background we may consider the question at issue. [fold]

Let us for convenience consider the relevant countries in dyads, beginning with the US-China equation. The US has overwhelming nuclear superiority in forces as well as technology, and the SSBNs that China can deploy against it will not seriously affect the balance between them for some time to come. If however China's SSBN program goes smoothly and it has five or six operational units in the next three or four years, that would be a significant challenge which the US would have to address. From a theoretical standpoint it is more destabilising when one nuclear power in a dyad has the overwhelming advantage, and China having a demonstrable ability to retaliate, albeit with a much smaller force, will reduce the possibility of a preemptive strike by an adversary. 

A similar situation exists with the India-China dyad. China's nuclear superiority rules out any first strike attempt by India. With a far smaller arsenal than China's, India is vulnerable to a first strike. The deployment of SLBMs will strengthen India's second-strike capability, on which it is largely dependent because of its 'no first use' policy. India is not pursuing parity in nuclear forces with China; if it did that would create arms race instability. The Indian SSBN program will not address the nuclear imbalance with China, but will improve strategic stability by giving India a credible ability to retaliate to a nuclear attack. 

The India-Pakistan equation is more fraught. Pakistan's nuclear arsenal is a little larger than India's and growing rapidly, according to the Bulletin of Atomic Scientists. According to reports, Pakistan also has a nuclear submarine building program, and although Pakistan has no known plan to deploy ballistic missiles at sea, there have been reports of plans to miniaturise a warhead for fitment on submarine-launched cruise missiles. Considering India and Pakistan share a long land border, and potential targets on both sides are a few minutes' flying time apart, it is hard to see how the Indian SSBN, when operational, would in any significant way change the nuclear stability equation. On the other hand, just as a destabilising element has been created on land by the introduction of Pakistan's Nasr tactical nuclear missile, if Pakistan does fit submarine-launched cruise missiles with nuclear warheads it would result in the delegation of the control of nuclear weapons to the tactical level and thus dangerously destabilise the situation.

To conclude: the deployment of sea-based nuclear weapons will not destabilise the nuclear balance in the Indo-Pacific provided this is restricted to ballistic weapons with centralised launch authority and the requisite command and control structures. The situation would, however, become extremely unstable by the arming of ships and submarines with nuclear-tipped cruise missiles.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

The dangers of SSBN proliferation in Indo-Pacific Asia

Published 11 Aug 2014 09:11   0 Comments


It has become commonplace to lament the arms races underway in Indo-Pacific Asia.

China's military modernisation over the last two decades has helped provoke heightened political tensions and growing concern in capitals from Tokyo to New Delhi to Washington and Moscow. North Korea's continued pursuit of nuclear weapons and missile delivery systems keeps tensions in Northeast Asia high. The Indian subcontinent is home to two nuclear powers that have fought four wars over the last 65 years. Many countries in the Asian littoral have undertaken serious rearmament programs, and across the region strategists see a proliferation of missiles of all types — anti-access systems, aerospace capabilities and naval platforms, among others. 

Regional nuclear modernisation programs, especially the development of submarines (nuclear powered or conventional) armed with nuclear weapons, are of special concern.

China and India are committed to producing more nuclear-capable delivery systems and weapons with greater range, accuracy and features that make them more lethal and thus more threatening to potential adversaries. Meanwhile Pakistan is pursuing its own program to acquire more capable submarines from China. While no one is arguing, as yet, that Pakistan intends to acquire ballistic missile submarines, some analysts hint that nuclear-tipped cruise missiles are a real possibility. Given Pakistan's record on nuclear proliferation over the past decades, such fears appear real. 

With the possible exception of America, powers external to the Indo-Pacific (Russia, for example) are also pursuing strategic modernisation. Russia, lest anyone forget, is an Indo-Pacific nuclear power by virtue of its Pacific Fleet, complete with its latest model SSBNs (in the American lexicon: Ship, Submersible, Ballistic, Nuclear), the Borei class, armed with Bulava missiles. Even the US is investing in the research and development preliminary to building a replacement for the Ohio-class submarines that currently constitute the sea-based leg of the American nuclear triad. American strategic modernisation is not a driver in the region's strategic dynamics, but insofar as the US is executing an Asian 'pivot', American military capabilities, nuclear and conventional, remain important. 

The emergence of strategic submarines in the Indo-Pacific is summarised in the following table. [fold]

This short post will not attempt a net assessment of regional or bilateral rivalries. A full analysis would need to look more closely at all dimensions of military power as well as the impact of American forces in the region. But a simple scan of the table above allows one small observation for a region that may soon be in the grips of a full-blown nuclear arms race. The prospects for stable, long-term peace (meaning greater strategic stability, the reduction of crisis instability, and fewer opportunities for accidents, chance and misperception to lead to conflict) depend, in part, on taking steps sooner rather than later to rein in potentially destabilising developments. At present, regional SSBN programs are not so advanced, and the numbers of platforms and weapons are not so large, that steps cannot avert a widening arms race. 

Growing numbers of submarines with nuclear-armed ballistic missiles may preserve second-strike capabilities for their possessors (and thus, debatably, contribute to strategic stability). But in the increasingly crowded seas of  Indo-Pacific Asia, greater numbers also lead to more opportunities for accidents, chance and misperception.

Submarine accidents are not unknown: the national tragedy of a lost boat and its crew might quickly become a regional or even global crisis if reactors or nuclear weapons have problems. Submarine operations in cramped seas also raise the possibility that one side or another will encounter the other in a crisis, with unpredictable results. Slowly maturing command and control (C2 ) and intelligence, surveillance, and reconnaissance (ISR) technologies still have a ways to go (look how long it took in US and the Soviet Union to develop their systems).

Furthermore, few speak of the challenge of ensuring the political and professional reliability of crews (while the mature nuclear powers rarely focus today on crew reliability, such concerns were quite real in the not-so-distant past). Nor are SSBNs and ballistic missiles in the Indo-Pacific the only aspect of undersea warfare and nuclear weapons that should trouble us: surface fleets, mine warfare, anti-submarine warfare and so forth increase the danger of incidents at sea, and they could raise the potential for a nuclear crisis. Knowledgeable analysts are concerned that the next stage of the Indo-Pacific naval arms race will involve still more submarines with nuclear sea-launched cruise missiles. 

Three 'nots'

If regional actors (not just the states currently pursuing SSBNs but other concerned parties) are to act to avert further arms racing and stabilise the emerging undersea deterrent, they must recognise the situation for what it is. A nuclear arms race at sea is:

  • Not simply a local or regional issue.
  • Not simply a military issue.
  • And not simply a navy or maritime issue.

A nuclear arms race at sea is a global problem with far-reaching implications for proliferation, conventional arms modernisation, and the possibility of arms control. The mere existence of such systems makes it more likely that the so-called nuclear taboo might finally be broken. An undersea nuclear race is deeply political because it affects the geopolitical rivalry among great and regional powers, not to mention alliance structures and patterns of regional governance.

For all regional military forces, such a nuclear arms race at sea is not simply the business of navies: SSBNs affect joint and combined operations in ways big and small, and blur important distinctions between conventional and nuclear systems. It is worrisome that despite some recent developments there has been, in general, asymmetric progress in developing weapons systems versus the C2, ISR, training/readiness, and nuclear doctrine necessary to deploy sea-based deterrent systems safely and reliably. 

Although prudence on the part of India, China and other regional powers may alleviate these concerns, it may not be sufficient for those interested in regional stability. In the end, although it is not fashionable to advocate for arms control much less naval arms control, strategists and policy makers should remember the words of Schelling and Halperin: 'the essential feature of arms control is the recognition of the common interest, of the possibility of reciprocation and cooperation even between potential enemies with respect to their militaries.' And, in the words of Robert Jervis, which seem especially prescient with regard to naval nuclear arms racing in the Indo-Pacific, 'because the security dilemma and crisis instability can exacerbate if not create conflicts, potential enemies will have an interest in developing arms control arrangements.'

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Image from Wikipedia.

SSBNs are unnecessary and destabilising

Published 7 Aug 2014 17:18   0 Comments

A Chinese Type 094 (Jin-class) SSBN. (Wikipedia.)

Regarding the Chinese and Indian ballistic missile submarine (SSBN) programs and their impact on international security, my arguments are: (1) they are not necessary; (2) noisy SSBNs are destabilising and should not be deployed; and (3) China's SSBNs are still far from being operational.

Chinese and Indian SSBNs are unnecessary because China-India and China-US strategic relations are stable, and will probably remain so in near future. While the Indian nuclear weapons program is driven by China's nuclear capability, it is America that drives China's nuclear development. Neither China nor India has first-strike capability against the other side, and neither side is seeking such capability. Some American nuclear and conventional strategic capabilities, such as missile defences and conventional prompt global strike (CPGS), do pose a big challenge of China's nuclear deterrent, but China can deal with these threats and restore strategic stability with its land-based nuclear missiles, which are relatively cheap and technologically mature compared to sea-based nuclear weapons.

So why are China and India developing SSBNs? The probable answer is that they are doing it for technology demonstration, national prestige, or bureaucratic competition purposes.

It is sometimes argued that SSBNs are a stabilising force, but this is the case only when the SSBN in question is quiet. Quiet SSBNs are difficult to find, giving leaders confidence that they will always have the ability to strike back should they be attacked, whereas noisy SSBNs are easy for an adversary to track, locate and destroy, encouraging a 'use it or lose it' mentality in times of crisis.

A declassified US Office of Naval Intelligence report from 2009 stated that China's Type 094 SSBN is so noisy that it is not survivable. China can use the Type 094 for technology demonstration or training purposes, but should not deploy it. India has yet to commission its Arihant-class SSBN, so we have no idea of its noise level. But if it too proves to be noisy, India should not deploy it either.

Furthermore, given China's lack of experience running an SSBN fleet, it needs to solve several problems in order to operate the Type 094s: [fold]

  1. Missile range: the range of the JL-2 sea-launched ballistic missile, which will arm the Type 094, is 7400km, not enough to hold the continental US at risk if launched from China's coastal waters. The Type 094 will have to get through the first island chain to target America, which would be dangerous, given its high noise level.
  2. Alert status: for land-based ballistic missiles, China separates nuclear warheads from their boosters in peacetime. Will China change this practice for SSBNs? Will China maintain a continuous-at-sea deterrent?
  3. Will China deploy a permissive action link (PAL)-like coded arming control device in its SSBNs? The advantage of the PAL-like system is to avoid unauthorised launch; the disadvantage is that the crew might be unable to launch missiles should the national command  authority or the communication system be destroyed.
  4. Deployment mode: will China deploy its SSBNs in 'bastions' protected by friendly forces, along China's coastal waters, or in open seas?

In sum, there are many problems for China to solve, all of which are complicated. China is unlikely to solve these problems in 10 to 20 years. I believe the current purpose of China's SSBN fleet is (and should be) to develop submarine-building technology and to train submariners in how to run an SSBN fleet. It is however too early to discuss the security influences of the Type 094.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Why sea-based nuclear weapons won't stabilise the Indo-Pacific

Published 7 Aug 2014 10:15   0 Comments

China, India and possibly Pakistan intend to deploy nuclear weapons at sea. Ultimately, such deployments may well have a stabilising effect — that is, they may reduce the risk of full-scale war and nuclear use. Sea-based nuclear weapons might, for instance, fit well with 'no-first-use' doctrines. They might also encourage reduced investment in more destabilising forces such as weapons fired from fixed sites, which are vulnerable and thus suited to a 'first strike'. And after all, sea-based nuclear weapons were widely seen as stabilising during the Cold War. 

However, we should beware of applying simple retrospective visions of the US-Soviet balance to the Asian strategic scene. There are various reasons to doubt that deployment of sea-based nuclear weapons in Indo-Pacific Asia will be stabilising. 

First, to state the obvious, there are three independent centres of nuclear power in Asia: China, India and Pakistan. And that is before counting the US and Russia, as well as North Korea, which one day could also want to base some of its weapons at sea. This fundamental element of the Asian nuclear scene will remain regardless of where weapons are based.

Second, although wanting the permanent presence of nuclear weapons at sea as a second-strike capability to guarantee their survival is arguably a stabilising factor, that may not be the driving motivation of all three countries. There seems to be strong interest in China and India, at least, in the symbolic value of strategic submarines, including for parochial or bureaucratic reasons. In addition, these two countries may prefer to avoid deploying nuclear-armed sea-launched ballistic missiles, in order to maximise political control over the weapons. It should also be added, regarding China, that the choice of a secure SSBN base on Hainan island, where berths are largely immune to a first strike, puts less pressure on Beijing to adopt a practice of continuous at-sea deterrence. 

Third, deployment of nuclear weapons at sea in Indo-Pacific Asia does not only mean strategic missiles based on submarines. [fold]

It may include cruise missiles on vulnerable surface platforms. It will also probably include theatre systems designed to target naval forces, notably by Pakistan. This would not be a stabilising factor if command-and-control dilemmas for such systems are resolved in a way that dilutes the ability of national authorities to maintain the highest degree of political control over the weapons at all times. It should be remembered that probably the closest call for the use of nuclear weapons since 1945 concerned naval theatre weapons: it was in Cuba in October 1962.

Fourth, Indo-Pacific waters lend themselves less easily to the deployment of non-detectable submarines than was the case for the Cold War confrontation, when the Atlantic and the Pacific oceans offered more opportunities. This is especially true since India and Pakistan are likely to field only medium-range systems for some time, forcing their submarines to operate relatively close to the adversary's shores. It is also worth mentioning that unlikely accidents can happen, as was the case in 2009 when British and French SSBNs collided, and it took them a while to realise what had happened.

More generally, the transition period towards the deployment of operational SSBNs by China, India and Pakistan is likely to be long, tortuous and dangerous, for technical and budgetary reasons. What happens if one (or two) of the three countries manages to have a secure sea-based second-strike capability well before the others? 

Simply put, it is impossible to argue that the deployment of sea-based nuclear weapons in Indo-Pacific Asia will be inherently stabilising.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia.

Image from Wikipedia Commons.

Sea-based nuclear weapons in Asia: Stabiliser or menace?

Published 6 Aug 2014 09:55   0 Comments

On this day in 1945, the first nuclear weapon was used in conflict, with devastating consequences for the people of Hiroshima. In Asia today, nuclear weapons remain part of the strategic reality, for better or worse.

But calculations about nuclear armaments in the region may be changing, notably with the introduction of Chinese and Indian submarine-launched nuclear weapons. This could have profound implications for whether nuclear weapons continue to help keep the peace or become instruments of instability and catastrophic escalation.

Often, strategic analysts and policymakers consider nuclear deterrence as somewhat separate from broader strategic and economic change. This has been all too apparent in the grand maritime region of Indo-Pacific Asia, where economic growth has been accompanied by tensions at sea, military modernisation and growing strategic differences among the powers.

Now, changes in the region are beginning to challenge traditional deterrence dynamics. Throughout the next decade, sea-based nuclear-weapon delivery platforms are set to proliferate in the Indo-Pacific, with China reportedly due to conduct its first at-sea nuclear deterrence patrol sometime this year, India readying for sea-trials of its first nuclear ballistic missile submarine, and even potential Pakistani interest in putting nuclear arms to sea.

Advocates of sea-based nuclear weapons see these fleets as providing stability because of their relative invulnerability to surprise attack. This is meant to provide a secure 'second strike' capability, ensuring that nuclear deterrence is credible and thus successful at preventing war.

But the picture is murky. [fold]

The implications of new sea-based nuclear weapons for deterrence, stability or instability will not be determined by those weapons systems alone. Investment in other capabilities like ballistic missile defences, anti-submarine warfare (including nuclear-powered attack submarines) and hypersonic missiles could complicate the picture. And much will depend on doctrines, the professionalism of personnel, and matters of perception and communication.

The nexus between new platforms, the factors driving their introduction and broader strategic realities raises the critical question of strategic stability. Will these new platforms, on balance, add to long-term stability in the region, greatly reducing the incentives for war or escalation, or will they contribute to the risks of crisis, arms races and coercion?

Will the deployment of an assured second-strike capability by India and China in the coming years lead to recognition of mutual vulnerability between them and also between China and the US? Or will sea-based nuclear weapon delivery platforms add to already heightened maritime tensions and risk? How will the shifting dynamics of nuclear deterrence interact with conventional force postures in the region? Are there stability-enhancing lessons to learn from the Cold War experience of the established sea-based nuclear powers?

In the weeks ahead, The Interpreter will host an international online debate to help answer these critically important questions. To open the debate, we have invited contributions from four leading scholars of strategy, maritime security and nuclear deterrence: Bruno Tertrais of the Fondation pour la Recherche Stratégique, Ravi N Ganesh of Asia Centre Bangalore, Wu Riqiang of Renmin University of China and Peter Dombrowski of the US Naval War College.

These initial posts will be followed by contributions from a range of security scholars and practitioners, and there will also be opportunity for the original contributors to reply and expand upon their arguments. Interpreter readers are also invited to join the conversation through the comments section, with the best comments to be featured in special posts. I hope the discussion, like our debate some years ago on extended nuclear deterrence, will prove lively, informative and of genuine value to policymakers.

Most of all, I hope it will help illuminate the way to measures that might minimise the risk that nuclear weapons will ever be used again.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia

Image courtesy of Wikipedia.