The Rise of U.S. Nuclear Primacy

Keir A. Lieber and Daryl G. Press

From Foreign Affairs, March/April 2006

Summary:  For four decades, relations among the major nuclear powers have been shaped by their common vulnerability, a condition known as mutual assured destruction. But with the U.S. arsenal growing rapidly while Russia's decays and China's stays small, the era of MAD is ending -- and the era of U.S. nuclear primacy has begun.

Keir A. Lieber, the author of War and the Engineers: The Primacy of Politics Over Technology, is Assistant Professor of Political Science at the University of Notre Dame. Daryl G. Press, the author of Calculating Credibility: How Leaders Assess Military Threats, is Associate Professor of Political Science at the University of Pennsylvania.

China's nuclear arsenal is even more vulnerable to a U.S. attack. A U.S. first strike could succeed whether it was launched as a surprise or in the midst of a crisis during a Chinese alert. China has a limited strategic nuclear arsenal. The People's Liberation Army currently possesses no modern SSBNs or long-range bombers. Its naval arm used to have two ballistic missile submarines, but one sank, and the other, which had such poor capabilities that it never left Chinese waters, is no longer operational. China's medium-range bomber force is similarly unimpressive: the bombers are obsolete and vulnerable to attack. According to unclassified U.S. government assessments, China's entire intercontinental nuclear arsenal consists of 18 stationary single-warhead ICBMs. These are not ready to launch on warning: their warheads are kept in storage and the missiles themselves are unfueled. (China's ICBMs use liquid fuel, which corrodes the missiles after 24 hours. Fueling them is estimated to take two hours.) The lack of an advanced early warning system adds to the vulnerability of the ICBMs. It appears that China would have no warning at all of a U.S. submarine-launched missile attack or a strike using hundreds of stealthy nuclear-armed cruise missiles.

Many sources claim that China is attempting to reduce the vulnerability of its ICBMs by building decoy silos. But decoys cannot provide a firm basis for deterrence. It would take close to a thousand fake silos to make a U.S. first strike on China as difficult as an attack on Russia, and no available information on China's nuclear forces suggests the existence of massive fields of decoys. And even if China built them, its commanders would always wonder whether U.S. sensors could distinguish real silos from fake ones.

Despite much talk about China's military modernization, the odds that Beijing will acquire a survivable nuclear deterrent in the next decade are slim. China's modernization efforts have focused on conventional forces, and the country's progress on nuclear modernization has accordingly been slow. Since the mid-1980s, China has been trying to develop a new missile for its future ballistic missile submarine as well as mobile ICBMs (the DF-31 and longer-range DF-31A) to replace its current ICBM force. The U.S. Defense Department predicts that China may deploy DF-31s in a few years, although the forecast should be treated skeptically: U.S. intelligence has been announcing the missile's imminent deployment for decades.

Even when they are eventually fielded, the DF-31s are unlikely to significantly reduce China's vulnerability. The missiles' limited range, estimated to be only 8,000 kilometers (4,970 miles), greatly restricts the area in which they can be hidden, reducing the difficulty of searching for them. The DF-31s could hit the contiguous United States only if they were deployed in China's far northeastern corner, principally in Heilongjiang Province, near the Russian-North Korean border. But Heilongjiang is mountainous, and so the missiles might be deployable only along a few hundred kilometers of good road or in a small plain in the center of the province. Such restrictions increase the missiles' vulnerability and raise questions about whether they are even intended to target the U.S. homeland or whether they will be aimed at targets in Russia and Asia.

Given the history of China's slow-motion nuclear modernization, it is doubtful that a Chinese second-strike force will materialize anytime soon. The United States has a first-strike capability against China today and should be able to maintain it for a decade or more.

INTELLIGENT DESIGN?

Is the United States intentionally pursuing nuclear primacy? Or is primacy an unintended byproduct of intra-Pentagon competition for budget share or of programs designed to counter new threats from terrorists and so-called rogue states? Motivations are always hard to pin down, but the weight of the evidence suggests that Washington is, in fact, deliberately seeking nuclear primacy. For one thing, U.S. leaders have always aspired to this goal. And the nature of the changes to the current arsenal and official rhetoric and policies support this conclusion.

The improvements to the U.S. nuclear arsenal offer evidence that the United States is actively seeking primacy. The navy, for example, is upgrading the fuse on the W-76 nuclear warhead, which sits atop most U.S. submarine-launched missiles. Currently, the warheads can be detonated only as air bursts well above ground, but the new fuse will also permit ground bursts (detonations at or very near ground level), which are ideal for attacking very hard targets such as ICBM silos. Another navy research program seeks to improve dramatically the accuracy of its submarine-launched missiles (already among the most accurate in the world). Even if these efforts fall short of their goals, any refinement in accuracy combined with the ground-burst fuses will multiply the missiles' lethality. Such improvements only make sense if the missiles are meant to destroy a large number of hard targets. And given that B-2s are already very stealthy aircraft, it is difficult to see how the air force could justify the increased risk of crashing them into the ground by having them fly at very low altitudes in order to avoid radar detection -- unless their mission is to penetrate a highly sophisticated air defense network such as Russia's or, perhaps in the future, China's.

During the Cold War, one explanation for the development of the nuclear arms race was that the rival military services' competition for budget share drove them to build ever more nuclear weapons. But the United States today is not achieving primacy by buying big-ticket platforms such as new SSBNs, bombers, or ICBMs. Current modernization programs involve incremental improvements to existing systems. The recycling of warheads and reentry vehicles from the air force's retired MX missiles (there are even reports that extra MX warheads may be put on navy submarine-launched missiles) is the sort of efficient use of resources that does not fit a theory based on parochial competition for increased funding. Rather than reflect organizational resource battles, these steps look like a coordinated set of programs to enhance the United States' nuclear first-strike capabilities.

Some may wonder whether U.S. nuclear modernization efforts are actually designed with terrorists or rogue states in mind. Given the United States' ongoing war on terror, and the continuing U.S. interest in destroying deeply buried bunkers (reflected in the Bush administration's efforts to develop new nuclear weapons to destroy underground targets), one might assume that the W-76 upgrades are designed to be used against targets such as rogue states' arsenals of weapons of mass destruction or terrorists holed up in caves. But this explanation does not add up. The United States already has more than a thousand nuclear warheads capable of attacking bunkers or caves. If the United States' nuclear modernization were really aimed at rogue states or terrorists, the country's nuclear force would not need the additional thousand ground-burst warheads it will gain from the W-76 modernization program. The current and future U.S. nuclear force, in other words, seems designed to carry out a preemptive disarming strike against Russia or China.