It was the Reagan administration that chilled foes and allies alike with the doctrine that a good missile defense makes the best nuclear offense.

Reagan's team came to office in 1981,vowing to cure the paradoxical impotence of the world's greatest nuclear power. Neutralized by the threat of mutual annihilation, America's tens of thousands of lethal warheads gave presidents no strategic advantage over their primary foe.

A reliable missile shield, the Reagan camp believed, could restore the nuclear advantage the United States enjoyed after World War II and turn the threat of nuclear "war-fighting" into a credible instrument of coercion in foreign policy.

In short, nuclear war had to become thinkable again.

In a speech to NATO officials a year before Reagan's election, Henry Kissinger waxed nostalgic about the days when "the United States possessed an overwhelming strategic nuclear superiority," which it used to dictate the outcome of foreign confrontations such as the Cuban missile crisis in 1962 or in the Middle East.

The Soviet achievement of nuclear parity and thus mutual deterrence, he said, was a foreign policy disaster, "a revolution in the strategic balance as we have known it."

Kenneth Adelman, who headed the Arms Control and Disarmament Agency under Reagan, joined other administration officials in rejecting the nuclear standoff as unacceptable.

The United States, he insisted, must show that it "would indeed risk nuclear escalation on behalf of foreign commitments."

Effective brandishing of nuclear threats required a credible ability to wage and win a nuclear war -- something most lay people and experts alike had considered suicidal.

The Reagan strategy called for "hardening" nuclear command and control systems, improving civil defense and building "counterforce" weapons such as the MX missile -- with nuclear warheads so accurate that they could demolish Soviet missiles in their silos.

The administration's "Strategic Defense Initiative," popularly known as Star Wars, was central to this strategy.

In 1985, administration adviser Colin Gray said on behalf of President Reagan's missile defense program that giving the American homeland "a growing measure of direct, physical protection" should strengthen "the willingness of U.S. presidents to run risks on behalf of distant allies."

More senior officials expressed the same doctrine in less striking language.

"By increasing the survivability of our strategic forces . . . strategic defense would help deter conventional aggression" by making a nuclear response feasible, said then-Defense Secretary Caspar Weinberger.

President Reagan similarly declared that "strategic defenses would strengthen the credibility of the U.S. extended deterrence," which is strategic speak for the use of nuclear weapons to deter enemies outside the United States.

In light of such doctrines, Moscow cannot help but wonder if Washington will someday try to take advantage of a missile shield to prevent Russia, say, from selling weapons to Iran.

China cannot help but wonder if the United States will brandish its nuclear superiority to defend Taiwan.

Both nuclear powers will have every incentive to neutralize U.S. superiority the cheapest way possible: by expanding their nuclear arsenals, setting off a new arms race.

A missile defense program could also bring out the worst in U.S. foreign policy by fostering illusions of a U.S. strategic advantage. An emboldened president might be more tempted to play "chicken" in conflicts of limited significance on the assumption that superior nuclear war-fighting capabilities gave him a free hand.

Unpredictable allies -- say, a nationalist firebrand in Taiwan -- could provoke a crisis based on the assumption of protection by America's nuclear umbrella.

But a miscalculation could have catastrophic results.

As former Defense Secretary Harold Brown once said, "I have always been concerned about massive ABM systems because I have always felt there was some possibility that some clever briefer could delude a political decision-maker into thinking that they were going to work."

The last thing the world needs is anyone imagining that nuclear war is thinkable.

President Bush betrays no such illusions.

But abandoning the ABM treaty in the faith that missile defenses are practical may well lead one of his successors to harbor such fanciful notions.

More certainly, the fear of such a prospect will prompt America's competitors to pursue an arms race to prevent Washington from dictating terms to them.

Foreign leaders with longer memories than President Bush's know that instead of ridding the world of the nuclear blight, ill-conceived nuclear "defenses" could needlessly increase the peril of nuclear war.

Jonathan Marshall of San Anselmo is a former Chronicle reporter who now handles public relations for a high-tech company in San Francisco.

©2001 San Francisco Chronicle

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