New Era of Defense Will Make Disputed Treaties Moot

The Reagan Administration’s declaration that it no longer considers itself bound by the provisions of the SALT II agreement introduces a new element of uncertainty into superpower relations and attempts to regulate the competition in armaments. Even more important was Defense Secretary Caspar W. Weinberger’s statement concerning the anti-ballistic-missile treaty--the statement that the Administration would not be interested in strengthening the 1972 U.S.-Soviet ban on most anti-ballistic missiles.

Coming on the heels of a reported Soviet offer that the two powers agree to lock in defensive limits while negotiating reductions in offensive arms, the Weinberger approach--before long all but certain to become official U.S. policy--marks a major change.

These events suggest a new chapter in the nuclear era. Four decades old, this era began with several years of American monopoly, which gave way to two decades of American superiority, only to give way again to the current phase of approximate U.S.-Soviet parity. The nuclear era has been characterized by two forms of proliferation: a vertical one, in which the two superpowers’ inventories increased not only in number but even more significantly in accuracy, dependability and speed, and a horizontal one, in which several other states joined or stopped just short of joining the nuclear club.

The nuclear era also has been characterized by a third phenomenon: the near-exclusive domination of offensive forces--above all, long-range intercontinental ballistic missiles. There was some exploration of defense against ballistic missiles decades ago, which was abandoned for lack of promise. The resulting reliance on offensive forces was enshrined in both doctrine--mutual assured destruction, or MAD, which posited that neither side would strike first so long as it knew that it could not escape devastating retaliation--and document--the 1972 ABM treaty, which severely constrained the anti-missile defenses of both the United States and the Soviet Union. Technology, theory and treaty thus combined to create a vast gap between offense and defense.

But developments are shaking the foundations of the nuclear era that we have known. New technologies, ranging from lasers to advanced computers, possess the potential to create some degree of useful defense against ballistic missiles. At the same time, arms-control pacts are unraveling. The Soviets have circumvented the ABM treaty or violated it, or both, through their construction of various radars while the United States has diluted the treaty’s effect by unilaterally defining as legal some activities that are inconsistent with the spirit of it. Over time, both signatories are sure to go even further beyond the treaty’s spirit or letter to determine the promise of defense-related technology. Finally, there is a decline in public support for deterrence as a strategy. Many Americans, including President Reagan, appear to reject the burdens and potential consequences of a policy that “accepts” Soviet possession and possible use of substantial numbers of nuclear weapons against a vulnerable America.

Where, then, are we headed? Probably not to a world as different from this one as the advocates of arms control or the critics of “Star Wars” predict. Offensive nuclear missiles are hardly about to become obsolete. The technical challenges to effective defense are awesome. Existing arms-control regimes will tend to fade gradually, not suddenly. Yet, given changing technologies and attitudes, the introduction of some partly effective anti-missile defense is inevitable. Indeed, such coexistence of offense and defense is the norm. For years each side has explored and maintained defenses--air defense versus bomber aircraft, active defense against submarines carrying ballistic missiles, civil defense to protect populations--that remain far from perfect; in the future we can expect much the same from anti-missile defenses.

What this will create is a world in which offense will continue to dominate, but less so. Without SALT, it could well be harder to calculate balances and more difficult to negotiate arms control. We may witness an increase in levels of offense as countries strive to counter new defenses. Yet there may be some good to be found in the prospect of enhanced defense. The vulnerability of retaliatory forces might be reduced. In addition, we would not have to navigate so dangerous a transition from a world of deterrence to one of mutual defense. We may also find ourselves with limited protection from accidental attacks as well as those by hostile third parties possessing modest but still destructive nuclear capabilities.

But, desirable or not, change is on its way. Thus far, the nuclear era has been an unprecedented one in which technology and politics united to provide offensive forces virtually unchallenged supremacy. We are now seeing the inevitable historical tension between offense and defense reassert itself. Just how much defense will challenge offense will for some time be impossible to determine. Until then, the prospects are diminished for arms control while deterrence, for years relatively inexpensive and taken for granted, is likely to grow more dear and difficult alike.