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.
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?
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.