How Defenses Lower Security
Even though the United States and Russia are scaling back their nuclear forces, the two countries still base their military relationship on nuclear deterrence. Both countries still rely primarily on nuclear-armed ballistic missiles to provide this deterrence. Moreover, there is no evidence that either country plans to move away from nuclear deterrence, despite growing pressure from the world’s non-nuclear nations for a commitment to nuclear disarmament. Russia is equally wedded to nuclear deterrence and views nuclear weapons as key to its superpower status and as a counterweight to its deteriorating conventional military strength.
This continued commitment to deterrence means that to whatever extent defenses threaten or appear to threaten deterrent forces, the same old problems will arise. Russia and China see as a fundamental security issue the need to preserve their ability to inflict a punishing nuclear retaliatory blow. It is therefore unlikely that these countries would sit idly by while the United States deployed a defense that they believed might render a retaliatory strike ineffective.
Russia would probably endow its missiles with countermeasures to protect them against U.S. missile defenses. A reliance on countermeasures, however, will introduce new uncertainties in Russian military planning. Russian leaders may find it implausible that the United States would be spending tens of billions of dollars on defenses that would be so easy to defeat. Thus, even if scientists and engineers are confident that their countermeasures would work, it is not clear they would be able to prevent Russia’s military and political leaders from responding in other, destabilizing ways as well.
While it can ill afford an arms buildup in response to U.S. missile defenses, Russia has other, less costly, options that could be equally problematic. Russia could, for example, increase its reliance on a policy of launch-on-warning or increase its alert rate, raising the chance of accidental and unauthorized launches. Moreover, Russia could simply refuse to cut its nuclear arsenal further. When Russia ratified the first Strategic Arms Reduction Treaty (START I), which cuts deployed forces to some 8,000 warheads, it made its fulfillment of the agreement contingent on continued U.S. compliance with the ABM Treaty. The START II agreement, which would cut deployed forces to 3,500 warheads, was ratified by the U.S. Senate but has run into deep political problems in the Duma (parliament) in part because of U.S. plans for missile defense. If Russia does ratify START II, the Duma will certainly link fulfillment of the treaty to preservation of the ABM Treaty.
Even if Russia were not concerned about U.S. missile defenses at START II or III force levels, defenses would almost certainly be a significant barrier to much deeper cuts in Russian (and hence U.S.) nuclear forces. As arsenals shrink, deterrent forces will become more vulnerable to even limited defensive deployments. Thus, those who argue that a limited U.S. national missile defense would entail no security costs since it would not threaten Russia’s large arsenal ignore the fact that U.S. security is best served by irreversible cuts in nuclear weapons to very low numbers-tens or perhaps 100. (Of course, some policymakers want to retain a large U.S. nuclear arsenal indefinitely and are thus unconcerned that missile defenses could preclude deep cuts.)
Even if Russia has finally agreed to a treaty modification permitting high-altitude defenses, deployment of such defenses could still stand in the way of deep cuts. That Russia has serious concerns about the strategic capability of these defenses is clear from the past three years of negotiations, and these concerns have presumably not evaporated despite Yeltsin’s concessions. Indeed, Russian agreement may only signify that it is comfortable with such defenses at START III force levels, and that it does not intend to cut significantly further.
The prospect of missile defenses might also cause Russia to keep open the option of expanding its arsenal in the future by refusing to agree on controls on the fissile material that nuclear weapons are made of. Russia might be reluctant to declare surplus much of its large existing stocks, for example. That would run counter to U.S. efforts to render its surplus fissile material difficult to re-use or steal, and its attempts to convince Russia to do the same.