Strategic stability (still) makes sense

I was a bit surprised when Liviu Horovitz wrote in Round 2 that reducing the nuclear arsenals of great powers is of limited importance to small, non-nuclear states such as Horovitz's own Romania. "[W]hat difference does it make," he wrote, "whether Russia can obliterate Romania 1,000 times or 2,000?" Well, it makes no difference at all—but whether a nuclear bomb is ever detonated in Romania certainly makes a difference. Progress toward disarmament reduces the risk of global nuclear war, so disarmament matters for every nation that doesn't want to be a nuclear battlefield.

Horovitz also questioned the value of strategic stability, portraying it as just one approach to the problems that nuclear weapons pose. But that is not how people such as Tatiana Anichkina and I—"stability seekers," in Horovitz's terms—see things. Stability seekers believe that maintaining strategic stability is an indispensable means of preventing nuclear arms races in peacetime and preventing nuclear war during crises. To be sure, policy makers would prefer to establish strategic primacy—the ability to completely destroy an adversary's nuclear weapons in a first strike. Policy makers, who don't enjoy being vulnerable to nuclear attack or retaliation, aren't very fond of strategic stability. But stable force structures make mutual vulnerability a fact, not a choice. Policy makers simply have to accept it.

During the Cold War, neither the United States nor the Soviet Union was able to achieve nuclear primacy, so strategic stability took the form of mutually assured destruction. In US-China relations today, standards are (and should be) different. China has never sought to reach strategic parity with the United States. Beijing's nuclear arsenal has always been modest in size and Chinese nuclear weapons are not kept on high alert. Indeed, China's nuclear arsenal does not even provide Beijing a guaranteed ability to retaliate against a nuclear attack. Instead, the Chinese arsenal provides only "first strike uncertainty." That is, the United States lacks full confidence that it could destroy all Chinese nuclear weapons while China lacks full confidence that at least one of its warheads would survive an attack. For now, there is enough uncertainty to maintain stability in Sino-US relations.

But a more effective US missile defense system, by reducing the odds that China could retaliate against a US attack, would have the potential to seriously upset Sino-US stability. The best way to forestall this danger is for the United States to accept limits on missile defense while China agrees to keep its arsenal small. Washington refuses to accept any limits—despite its frequent expressions of willingness to discuss missile defense with China.

The root of the problem is that some US strategists wish to establish nuclear primacy over China. This makes US administrations reluctant, vis-à-vis China, to publically utilize the term "mutual vulnerability." So the United States can only offer China an ambiguous, flexible form of strategic stability.

Because of attitudes that prevail in the United States, US missile defense is likely to expand as fast as technology advances. It will be constrained only by budgets. I fear the worst possible outcome: that the United States steadily and unilaterally deploys greater missile defense capabilities and China responds by constructing more nuclear weapons.