China’s Underground “Great Wall”: A Success for Nuclear Primacy

Oct 25, 2011


By Eli Jacobs
Nuclear security analysts are becoming increasingly worried about China’s development of a 3000-mile underground “Great Wall” to shelter their nuclear weapons. The tunnel network introduces serious doubts about the United States’ ability to carry out a disarming nuclear first strike against China, by introducing uncertainty about the number of Chinese weapons, their location within the underground fortress, and the capability of U.S. weapons to penetrate into the bunker.
Despite complicating the effectiveness of a U.S. first strike, the Chinese construction of a tunnel system validates the strategy of seeking nuclear primacy over China. By forcing the Chinese pursuit of numerous defensive measures to ensure second-strike capability, the United States reduces the amount of money China can spend to improve their nuclear weapons. The resulting relative lack of appealing first-strike options may make China think twice before escalating from conventional to nuclear war and, more significantly, may dissuade China from creating conditions that could produce conventional conflict in the first place.
The orientation of Chinese nuclear policy is largely defensive. The tunnel network is the capstone of a long-term project to create a mobile, sheltered nuclear arsenal that is less vulnerable to first strike. This project has seen them construct a nuclear submarine capability and a variety of short- and intermediate-range mobile missiles that could be used to attack U.S. allies or forward-deployed military forces such as aircraft carriers. Importantly, although China is developing long-range road mobiles, these weapons are numerically de-emphasized, with a primary emphasis on short-range ballistic missiles. This suggests that China is focusing on defending their homeland and interests in their near-abroad rather than attempting to achieve parity with U.S. nuclear forces.
A recent Wall Street Journal op ed opines that China’s massive network of tunnels indicates a secret, hostile motive:
One kilometer of tunneling is approximately equal to the cost of four or five nuclear weapons and certainly several delivery systems," [Karber] notes. Why would China devote such vast resources to building a protective network of tunnels, while devoting comparatively few to the weapons the tunnels are meant to protect?
To me, the more plausible reading of this statement is to conclude that China has likely spent so much money on tunneling that it has not been able to spend significantly on the development of offensive nuclear capabilities – such as low yield warheads or long-range ballistic missiles. Their current strategy is centered on self-defense in the event of a war over East Asia. If China did not fear losing this war, they would have greater capabilities to prepare to fight different ones – including, perhaps, strategic nuclear wars against the continental United States.
China’s declaratory policy of “No First Use” matches this assessment of their current defensive orientation. Although there are a number of circumstances when China would consider abandoning its declaratory policy – when it’s facing defeat in a conventional war, for example – the existence of the pledge goes quite a ways in shaping Chinese strategic discussions. Intellectuals do not typically ponder nuclear first-strike contingencies. As a result, should a circumstance arise that may make China contemplate abandoning NFU, they may not possess the strategic consensus required to be confident in the efficacy of various first-strike options. This reality may make China hesitate to escalate to nuclear conflict and, more significantly, it may make Beijing think twice before initiating a conflict that might result in circumstances where it would need to rethink its NFU promise.
China’s nuclear capabilities follow from the retaliatory, second-strike approach of its defense posture. Estimates place China’s nuclear stockpile at 250-400 weapons, a fraction of the 1550 strategic weapons the United States deploys under New START. An arsenal this size could do significant damage to the United States and our allies, but it is not large enough to achieve strategic victory in a nuclear war with the U.S.
Some might attribute this defensive emphasis to Chinese strategic culture. Indeed, the relative consistency of their nuclear doctrine since testing in 1964 suggests that cultural factors may play a role in sculpting their nuclear decision-making. However, debates among Chinese strategists about whether to maintain minimum deterrence or adopt a slightly more robust limited deterrent indicate the opposite: Chinese defense policy has a certain degree of fluidity. In that vein, it would be extremely short-sighted for the United States to follow a singular narrative of Chinese nuclear strategy in adopting policies that incentivize a shift away from China’s primarily defensive nuclear planning.
China’s stated intention for building its massive underground tunnel is to ensure second-strike capability against the United States. Given the importance of this underground network to China’s nuclear weapons complex (they’ve been working on it since 1995), it’s fair to assume that similar motives guide China’s overall nuclear policy.
However, it is unwise to expect the centrality of these motives to persist into perpetuity. A changing international environment may prompt China to reevaluate their defense goals. Pro-engagement commentators make this argument. For instance, Carnegie’s Michael Swaine argues:
China’s strategic mindset is quintessentially defensive, largely reactive, and focused first and foremost on deterring Taiwan’s independence and defending the Chinese mainland, not on establishing itself as Asia’s next hegemon. Although it is not inconceivable that China might adopt more ambitious, far-flung military objectives in the future—perhaps including an attempt to become the preeminent Asian military power—such goals remain ill-defined, undetermined and subject to much debate in Beijing. This suggests that China’s future strategic orientation is susceptible to outside influence, not fixed in stone.
As a result of this malleability, Swaine suggests that the United States should “shape a ‘mixed’ regional approach focused more on creating incentives to cooperate than on neutralizing every possible Chinese military capability of concern to U.S. defense analysts.”
I would like to suggest a different interpretation of this malleability. Given their growing economy, China will have increasing means to acquire greater economic and military leverage over international events. It serves their national interest to take advantage of these opportunities. At many junctures, the United States national interest will compete with China’s – over economic issues such as Asian market access and over military issues such as forward deployment of naval power and the status of Taiwan.
Although cooperation must play an important role in the United States’ relationship with China, it is unrealistic to expect countries that are so economically powerful yet politically divergent to agree over all critical international issues. High-stakes disagreements are inevitable. Most of these will be resolved without violence, if not amicably, based on an assessment by either side of the potential risks and rewards of taking an openly combative stance.
One way that China can limit U.S. freedom of action in these disputes is to develop greater offensive nuclear capabilities – such as more and low yield warheads and more long-range ballistic missiles – and work towards nuclear parity with the United States. Even though the U.S. nuclear arsenal would likely still outstrip China’s, the possibility of a costly and uncertain escalation (as opposed to a situation in which the United States possessed escalation dominance) may prevent the United States from intervening in issues that are of greater importance to China than to the United States, such as Chinese attempts to stabilize the DPRK regime or develop amphibious weaponry for a potential attack of Taiwan.
Given their greater resources, superior nuclear forces will serve China’s national interests regardless of U.S defense policy. Fortunately, U.S. nuclear primacy helps to change the valence of that build-up, orienting it towards a defensive stance by making it too expensive to develop useful but non-essential offensive nuclear capabilities.
The grave threat of U.S. nuclear first strike is, thus, a contributor to China’s current defensive nuclear posture. Ceasing the pursuit of primacy would serve as a de facto acknowledgement of mutual vulnerability; it would free up resources for China to make progress on other, more offensive components of its arsenal. These measures, pursued in the absence of a U.S. nuclear first strike option, would give China the means to prepare for nuclear first-use contingencies. This would not only make them more confident about last-ditch escalation to nuclear war in a failing conventional conflict, but also give them less pause about initiating conflicts, given their expectation of greater freedom of action.
In short, forcing China to plan to defend itself against U.S. first strike orients their strategic culture around defensive as opposed to offensive posturing and reduces their means to invest in offensive nuclear capabilities. Thus, while China’s tunnel network reduces the likelihood that the United States possesses nuclear primacy, it is a form of strategic tunnel vision to argue that we should, as a result, accept a reality of mutual vulnerability. Continuing to introduce meaningful doubt into China’s understanding of the security of their deterrent forces them to spend to protect it, rather than spending to threaten or compete with the United States.
So, given China’s 3000 mile tunnel system, can we continue to introduce this meaningful doubt into China’s defense calculus? I think so. Current anti-tunnel technology, used most prominently by the Israelis to prevent smuggling of arms into Gaza, is used locally and is surprisingly ineffective. The United States faces an even greater challenge than Israel: it cannot continuously bombard China’s tunnel network in the way that Israel continuously bombards smuggling tunnels into Gaza, because that could jeopardize crucial areas of cooperation with Beijing and may even be understood as a precursor to preventative nuclear first-strike.
However, technological development in anti-tunnel technology has been constant. A new two-component explosive that can be planted remotely seems promising, and further developments could be achieved through concerted research. Further, a good deal of information exists about China’s underground missile base, to which the tunnel network is a mere corollary. Holding this base at risk with earth penetrating nuclear weapons such as the B61-11 would call into question China’s second-strike capability. Further, entrances and exits to the tunnel system could be identified through satellite surveillance. Triangulation between various tunnel entrances and known missile base information could guide barrage nuclear strikes that close off the tunnels, even while not fully destroying them.
In brief, despite China’s tunnel system, we should not abandon the pursuit of nuclear primacy over China. While the scope of their tunnel system suggests that China could pose an increasing nuclear threat, it also suggests, more importantly, that our current strategy is working in compelling them to develop defensive as opposed to offensive nuclear capabilities.
Eli Jacobs is a research intern for the Project on Nuclear Issues. The views expressed above are his own and do not necessarily reflect those of the Center for Strategic and International Studies or the Project on Nuclear Issues.