Missile defense capabilities and offensive arsenals are inextricably linked together. Limits on missile defense have long been at the center of demands from Russia and China. The United States and NATO have expressed particular interest in limits on Russian non-strategic nuclear weapons. Some form of compromise between the two will likely be at the core of a broader package of strategic stability measures.
After more than six decades of research – and nearly 20 years since the demise of the ABM Treaty removed any legal restraints on its development – missile defense continues to prove ineffective against the strategic offensive forces of the major powers while nevertheless exerting a destabilizing long-term influence on the strategic balance. Given this situation, it is in the interests of all the major powers to take steps to limit the growth of missile defense capabilities in a way that substitutes mutually agreed restraints for the current de facto limits imposed by long-standing technological challenges and budget constraints. This will help stabilize the offense-defense balance globally while sacrificing little in terms of real future defensive capability.
A number of measures, primarily between the United States and Russia, could help to limit the uncertainty over future missile defense capabilities by placing more explicit restraints on today’s limited missile defenses so that they cannot expand into systems that could put the retaliatory capability of any of the five nuclear powers at risk.
These steps could include confidence-building measures, such as transparency agreements and reciprocal observation of missile defense interceptor tests, a ban on space-based missile defense interceptors, clearer unilateral explications of the extent and limits of both Washington and Moscow’s missile defense plans, as well as negotiated limits on missile defenses on either a legally or politically binding basis.
Given their long-standing interest in missile defenses designed to counter only limited threats and the risks that an offense-defense competition could pose both to stability in the North Atlantic area and the viability of European members’ nuclear arsenals, U.S. NATO allies should do all they can to support these efforts.