It used to be the left that ridiculed MAD, the nuclear strategy of "mutually assured destruction." The anti-nuclear movement of the early 1980s blindsided the political establishment like the anti-global-trade movement of the past couple of years. Ronald Reagan's original Star Wars proposal was an act of political jujitsu, attempting to co-opt public fear of the nuclear standoff on behalf of military hardware instead of treaties or (worse) unilateral disarmament.
This didn't work—mainly because the hardware didn't work. But strategic defense, and ridicule of MAD, became essential elements of the American conservative theology. The flame of faith was kept alive through the cold 1990s by movement monks at Washington think tanks and devotional conferences around the world. Silent prayers were said in the offices and boardrooms of defense contractors throughout the land.
Now, the second coming. President Bush doesn't pretend or imagine, as Reagan did, that strategic defense can be an "invisible shield" that would free us from all physical danger of nuclear attack (and thus, if we wished, from all moral danger of having to threaten one). Nevertheless, in his speech Tuesday, he twice described the "grim premise" of MAD as a historical relic.
It is not. As long as we have no Reaganesque perfect shield, we still live in the world of MAD. And as long as we live in that world, MAD complicates the case for strategic defense in ways Bush does not acknowledge. MAD is underappreciated. It is not simply a matter of the nuclear powers agreeing to hold each other hostage. In fact "agreeing" has almost nothing to do with it. The 1972 ABM Treaty, which is getting so much attention, did help to make the nuclear stalemate somewhat less costly and nerve-racking. But the stalemate itself—our ability to destroy any other nation in the world, and at least one other nation's ability to destroy us—would exist without the ABM Treaty and will exist even if we walk away from it.
Furthermore, under the theory of MAD, we leave ourselves vulnerable in certain ways not because we have no choice, and not because we've agreed to do so, and not because protecting ourselves might upset the Europeans, but because it is in our own unilateral self-interest. Specifically, it is important to be vulnerable to a "second strike"—that is, a retaliatory strike by an arsenal crippled by your potential "first strike." Why? Because you don't want anybody with nukes pointed at you to think they have to use 'em or lose 'em. As long as they can rain cataclysmic damage on us by striking second, they have no more incentive than we do to strike first.
The concern in the 1980s was that strategic defense would never be good enough to protect against a massive first strike but might be good enough to protect against a crippled second strike. If America had the ability to strike first and then be invulnerable, any nuclearized enemy in a crisis would face the choice of either starting a nuclear war or accepting defeat. The approach of such American invulnerability might even cause such a crisis, as other nuclear powers faced the prospect of being effectively demoted out of the nuclear club.
It's true that the world is different now. Russia is hardly the enemy that the Soviet Union was, and there are new—or at least newly noticed—threats from so-called rogue nations and kooky dictators. But that also does not change the basic logic of MAD. President Bush says he wants to negotiate radical mutual reductions in the nuclear arsenals of the United States and Russia. Good luck to him, by all means. But is he prepared to negotiate away our ability to launch a damaging first strike? If not, any defense that might work even against a crippled retaliation is a danger to the United States as well as to Russia.
And then there's China—a major unofficial target of the whole Star Wars II enterprise, and leading contender for the starring role in Cold War II, which hopeful ideologues are penciling in for later this decade. If that should happen, the perverse-but-solid safety-from-vulnerability logic of MAD will apply in full force.
So, we can't have a perfect invisible shield. And we don't, or shouldn't, want an imperfect invisible shield good enough for Round 2 against Russia or China or any other grown-up nuclear power. It would be nice to have a strategic defense system just good enough to be able to snare a nuke incoming from an Iraq or Afghanistan—and no better. But even that dream defense would only work if the bomb is delivered via ICBM, which may be less likely than BMW or UPS.
There's no good reason for theological objection to strategic defense. But when you add up all the situations where it can't or shouldn't be allowed to work, factor in the odds that it won't work at all, and start thinking about the cost, its theological enthusiasts seem to be making a leap of faith the country needn't follow.