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.