Why Even Good Defenses May Be Bad

DefensesMay Be Bad 1 O n c e again, the United States is in the midst of a debate over whether to deploy defenses designed to protect U.S. cities and population from Soviet missile attack. This debate is, most immediately, the result of President Reagan’s “star wars” speech, in which he asked the rhetorical question: “wouldn’t it be better to save lives than to avenge them?” He offered a future vision of ”truly lasting stability” based upon the ”abilityto counter the awesome Soviet missile threat with measures that are defensive.”IJust six months later a senior interagency group recommended to the President that the ”U.S. embark on early demonstrations of credible ballistic missile defense technologies to its allies and the Soviet Union.”2 There is, in addition to this most recent catalyst, a deep-seated, enduring reason why the possibility of defending the United States from Soviet nuclear attack is a recurrent issue. Put most simply, it is quite natural for the United States to want to remove itself from a situation in which the Soviet Union has the capability to virtually destroy it. The United States cannot, today, physically prevent the Soviet Union from wreaking such destruction. U.S. security therefore depends upon its ability to deter Soviet nuclear attack. If deterrence works, then the United States will be able to avoid nuclear war with the Soviet Union. Unfortunately, the possibility that deterrence could fail cannot be easily dismissed. Deterrence will have to work for decades and centuries-that is, unless the current situation, in which the United States is vulnerable to Soviet nuclear attack, is dramatically altered. While one cannot The author would like to thank Robert Art, Albert Carnesale, Lynn Eden, Michael Nacht, Thomas Schelling, Stephen Van Evera, Stephen Walt, and the members of the Avoiding Nuclear War working group for their helpful comments on earlier drafts of this article. Charles L. Glaser is a Postdoctoral Fellow on the Avoiding Nuclear War Project at the John F. Kennedy School of Government, Harvard University, and a Research Fellow at the School‘s Center for Science and International Affairs. 1. The New York Times, March 24, 1983, p. 20. 2. Clarence A. Robinson, Jr., ”Panel Urges Defense Technology Advances,” Aviation Week and Space Technology, October 17, 1983, p. 16. InfernntionnlSecurity, Fall 1984 (Vol. 9, No. 2) 0162-2889/84/020092-32$02.50/1 8 1984 by the President and Fellows of Harvard College and of the Massachusetts Institute of Technology. 92 Why Even Good Defenses May Be Bad I 93 specify with confidence the way in which the superpowers’ nuclear arsenals might come to be used, knowing that deterrence could fail in a variety of ways is sufficient to create a feeling that, given enough time, deterrence will fail. Consequently, as long as the United States remains vulnerable to Soviet nuclear attack, the possibility of nuclear attack will create an interest in defense against it. The current debate over the deployment of ballistic missile defense (BMD), like the one in the late 1960s, is highly polarized. Defense, according to its opponents, is undesirable on all scores. They argue that defense will not work effectively, will increase the probability of war, and will cause arms races. Proponents, on the other hand, see few, if any, disadvantages with defense. They argue that defense will reduce the damage the Soviet Union could inflict on the United States, will not increase the probability of war and might decrease it, and might even improve the prospects for achieving arms control agreements which limit offensive nuclear force^.^ The vast majority of the debate has pivoted on the technological feasibility of effective BMD. The implicit assumption is that if effective BMD could be developed and deployed, then the United States should pursue the BMD route and the associated change in its nuclear ~trategy.~ The principal argu3 . A ballistic missile defense is a system capable of destroying Soviet missiles (or warheads) in flight. The terms “ballistic missile defense” (BMD) and ”anti-ballisticmissile” (ABM)are usually used interchangeably. BMD programs which might contribute to the goals described in President Reagan’s so-called “star wars” speech are also referred to as the Strategic...