No China mod impact---it’s constrained and defensive.

This modernization program has raised concerns over the past several years that China is currently attempting or might soon attempt a nuclear breakout. Concerns of a Chinese breakout come in two forms: either that Beijing will develop a nuclear warfighting capability that could neutralize U.S. conventional superiority, or that Beijing will expand its strategic arsenal to achieve parity with the United States, which could undercut U.S. security commitments to its regional allies.

While China is indeed in the midst of a significant modernization effort, the changes to its nuclear forces do not yet represent a fundamental strategic shift. Rather, China’s nuclear evolution appears to be driven by a desire to maintain a secure second-strike capability in the face of advancing U.S. capabilities, which Beijing believes might threaten its nuclear deterrent. As I demonstrate in a new article in the Nonproliferation Review, China’s nuclear arsenal and strategy are constrained by its limited views of the utility of nuclear weapons. Moreover, Beijing would face several “harder” technical constraints in pursuing the kind of nuclear breakout about which some commentators warn.

Concerns of an Impending Chinese Breakout

First, some commentators have argued that China may be currently developing a nuclear warfighting capability, or at least the nuclear arsenal to support one. A nuclear warfighting capability can refer to either a force designed to attack an adversary’s nuclear arsenal, or a nuclear force designed for use on the battlefield, though most commentators mean the latter when referring to China. These developments, they argue, could lead to China introducing nuclear weapons into an otherwise conventional conflict.

Other observers have contended that China may attempt a “sprint to parity,” a rapid buildup in its strategic nuclear arsenal until it has roughly as many nuclear weapons as the United States (One scholar has even fantastically claimed, based on an analysis of the underground tunnel system designed to protect China’s missiles, that it may already possess more than 3,000 nuclear weapons). This would entail a dramatic expansion in the size of China’s nuclear arsenal.

China’s Current Nuclear Posture

China’s nuclear forces and policies are constrained, first and foremost, by the country’s distinctive approach to nuclear weapons. As Jeffrey Lewis has written, Chinese leadership has historically believed that nuclear deterrence is largely unaffected by the size and configuration of the adversary’s nuclear arsenal, so long as the country can threaten a counterstrike of a few – or even one – nuclear warheads. Marshall Nie Rongzhen, a leading figure in China’s early nuclear weapons program, called this “the minimum means of reprisal.” Recent research by Fiona Cunningham and M. Taylor Fravel, based on reviews of Chinese doctrinal and academic writings and interviews with Chinese military and civilian experts, indicates that these fundamental views have not changed and that China is likely to continue adhering to its relatively restrained strategy of “assured retaliation.” In recent Track-1.5 and Track-2 dialogues between the United States and China, Chinese participants have said that China could credibly threaten the United States with only “a few,” a “handful of,” or even “one” nuclear warhead.

Designed to support more limited goals, China’s nuclear forces are generally believed to be smaller and less alerted than those of other states. The country has yet to develop an early warning system and some experts believe China would wait several days after suffering a nuclear strike before launching its own nuclear counterattack. Observers believe Beijing does not mate its nuclear warheads to missiles in peacetime, instead storing them separately. According to the counting rules of the New START treaty, China has nearly zero deployed nuclear weapons.

China’s ongoing nuclear modernization program is indeed significantly changing the character and configuration of the country’s nuclear forces. But these changes appear to be driven by a desire to maintain the survivability of the country’s second-strike capability, not a fundamentally new view of nuclear weapons in Beijing. China has identified advancing U.S. capabilities in conventional prompt global strike and ballistic missile defense as serious threats to its nuclear forces. Regardless of whether these concerns are reasonable, they appear sincere. By deploying more mobile missiles, China hopes to increase the survivability of its overall deterrent. By deploying SSBNs and equipping some of its land-based missiles with MIRV capability, it hopes to enhance its ability to penetrate U.S. missile defenses.