STABILITY?
Yet another criticism of the narrower understand-ing of strategic stability is that it is only a useful tool for policymakers if other states share the U.S.
concep-recently been advanced by David Yost with regard to the U.S.-Soviet relationship during the Cold War.
Central to Yost’s argument is a considerable body of evidence that “the Soviet political-military leadership appears to have rejected the ‘mutual assured destruc-tion’ reasoning advanced by Robert McNamara and his followers as the desirable foundation of strategic stability, including ‘crisis stability’ and ‘arms race stability’.”48 The salient question here is whether this rejection actually nullified the utility of U.S. policies designed to promote stability.
In an attack on the concept of arms race stability, Yost observes that the Soviet nuclear arms build-up of the 1970s “did not conform to U.S. ‘arms race sta-bility’ theories” and “gave many American observers the impression that the USSR was seeking superior-ity.”49 Soviet behavior was indeed confounding to some in the United States. A number of American analysts originally assumed that the primary—if not the sole—reason for the Soviet build-up was enhanc-ing the survivability of its nuclear forces. Given that the drivers for Soviet procurement were actually more complex, it was inevitable that these analysts would be disappointed when the Soviet Union did not termi-nate its build-up upon acquiring a survivable second strike capability.50 However, Yost’s observation says much more about a lack of imagination on the part of American analysts than it does about any deficien-cies with strategic stability. As noted above, there are plenty of reasons why a state might build up its forces besides fear of an adversary’s first strike and nothing in strategic stability “theory” says otherwise (a point that some over-enthusiastic advocates may have for-gotten). Achieving an assured second-strike capability was a necessary condition for the Soviet Union to cease
its arms build-up but certainly not a sufficient one. Ac-cordingly, Soviet behavior in the 1970s is not a valid reason for rejecting the concept of arms race stability.
Ultimately, whether states stop an arms build-up after achieving an assured second-strike capability is not really a fair test of the usefulness of arms race sta-bility. A better test is to examine whether states that fear for the survivability of their forces start an arms build-up. The U.S.-Soviet experience from the Cold War certainly meets this criterion. As noted above, a major factor in precipitating the Soviet long-range arms build-up appears to have been concern in Mos-cow that, at the height of the Berlin Crisis in 1961 and during the Cuban Missile Crisis in 1962, the vulnera-bility of its forces had proved a significant disadvan-tage.51
The motivation of the Soviet Union in continuing to augment its nuclear forces long after it had achieved a credible second-strike capability forms the basis for Yost’s critique of crisis stability. Yost points to con-siderable evidence that the Soviet Union adopted a warfighting doctrine, which, he argues, led it to seek superiority in order to limit the damage it would suf-fer in a nuclear war.52 By contrast, he claims that the United States “at times exercised restraint” in devel-oping equivalent counterforce capabilities, although, strangely, he gives just a single minor example of such restraint and glosses over continual and relentless improvements in U.S. missile accuracy that far out-stripped the Soviet Union.53 In light of this disparity, Yost argues that a “shared commitment to a theory of ‘crisis stability’” cannot explain the absence of con-flict.54 Instead, he attributes it to the bipolar structure of the Cold War international order and the “profound
Contrary to Yost’s explanation, however, it is precisely because the Soviet Union had a warfighting doctrine that it was important to ensure crisis stability during the Cold War.56 As Yost himself observes, the Soviet Union was prone, rightly or wrongly, to pro-ject its own dedication to nuclear warfighting onto the United States.57 Had the Soviet Union come to believe that the United States was about to strike then—ac-cording to Yost’s own interpretation of Soviet doc-trine—it may have tried to pre-empt such an attack.
In a crisis, therefore, it was critically important for Moscow to believe that Washington thought it could not meaningfully lessen the horror of a nuclear war by striking first. Thus, crisis stability is not inconsist-ent with Yost’s explanation that the Cold War did not turn hot because each side had a profound fear of nu-clear war. On the contrary, it is precisely because there generally was a sufficient degree of crisis stability that this fear was able to play a restraining role.
Of course, to the extent that the Soviet Union did not accept mutual vulnerability as a policy goal and sought to attain superiority, it was, as a practical matter, harder for Moscow and Washington to agree upon bilateral measures to enhance stability. Howev-er, such measures were negotiated—most notably the Anti-Ballistic Missile Treaty and START I—and they played a positive if modest role in enhancing strategic stability, even if the Soviet Union was motivated to agree to them for other reasons. Moreover, the Soviet Union’s failure to accept mutual vulnerability certain-ly did not stop the United States from taking unilateral steps to enhance strategic stability, such as developing SSBNs (which, until the final years of the Cold War, were particularly stabilizing because they were too inaccurate to threaten an adversary’s strategic forces).
In fact, the development and procurement of surviva-ble nuclear forces—unilateral decisions originally tak-en outside of an arms control framework—did more than anything else to ensure mutual vulnerability and hence crisis stability during the Cold War.
CONCLUSIONS
It might have been better if strategic stability had an alternative, less grandiose name (“deterrence sta-bility” springs to mind as one alternative). The very words “strategic stability” give the impression of a broad concept that pretends to predict whether and how states can enjoy stable relations. In reality, how-ever, strategic stability is most useful if it is narrowly defined—in terms of whether fear of an adversary’s using nuclear weapons motivates a state to change its force posture—and modestly applied, that is, with the recognition that it is one—and not the only—criterion against which to assess nuclear policy.
While fear of an adversary’s first strike has nev-er led to nuclear use, it has led states to change their force postures in sometimes dangerous ways, whether by dispersing mobile forces, redeploying existing sys-tems or developing entirely new ones. None of these actions have been cost free, not least because they have sometimes exacerbated international tensions and cre-ated new risks of further escalation. Reducing similar pressures on states in the future—that is, ensuring and enhancing strategic stability—remains a worthwhile, and in fact a vital policy goal.
That said, it is not the only relevant goal. Nuclear strategy must also be assessed along other axes—de-terrence effectiveness, cost effectiveness, bureaucratic
name but five—and we should certainly not assume a priori that the policy that maximizes strategic stabil-ity will simultaneously maximize all—or even any—
of the other variables. Crafting the optimal nuclear strategy almost certainly involves trade-offs and it is by defining strategic stability most narrowly that we are most likely to set up a sensible debate about what those trade-offs should be.