The Feb. 20 shoot-down of a toxic-fueled satellite was an amazing technical accomplishment. Think of it: An SM-3 missile, fired from a cruiser in the Pacific Ocean, ascending 133 miles and colliding dead-on with an object the size of an SUV that's zooming through outer space at 17,000 miles per hour. Truly remarkable!
But does it say much, as some have claimed, about our ability to shoot down ballistic missiles fired at American (or allied) shores by a nuclear-armed enemy? Not really.
The SM-3 that shot down the satellite was, in fact, designed—is part of the overall program—to shoot down ballistic missiles. But, as Gen. James Cartwright, vice chairman of the Joint Chiefs of Staff (and former commander of Strategic Command, the agency that runs the missile-defense program's operations), said at a Pentagon press briefing on Thursday, the SM-3 had been "modified" to shoot down the satellite. As reconfigured, he said, it was "not a missile defense system." The two tasks "do not correlate." The profile of the target and the nature of the intercept were "very different."
One reporter asked, "Does the whole episode then add to the knowledge that could be used or applied to missile defense at all?"
Cartwright replied, "Other than netting the sensors together, which is what we used for missile defense"—and which has been tried out in many previous missile-defense tests—"not really. I mean, it doesn't cross over."
Let's back up. The SM-3s, which are based on the Navy's Aegis-class cruisers, have been the most successful weapons in the multilayered missile-defense program. They have hit their target—a mock warhead—in 11 of their last 12 tests. The Pentagon didn't need to fire one against a satellite—a mission that involved much modification in its software—to show that, within the parameters of the test, it works.
But let's back up further. The challenge of a missile-defense program is not to "hit a bullet with a bullet." That feat, remarkable as it is, was demonstrated some time ago. The challenge is to hit several bullets with several bullets in a short period of time. To drop the metaphor, it's to hit several warheads—each the size of a small refrigerator (much smaller than the satellite and thus much harder to find, track, and hit)—some of which might be zooming alongside decoys that might be very hard to distinguish from the warhead. (The missile defense agency has yet to conduct tests against any but the crudest decoys.)
And another challenge is to hit warheads that an enemy might fire from a surprise location—perhaps outside the easy range of our anti-missile interceptors. For instance, an enemy might fire missiles from a boat a few hundred miles (and, therefore, only a few minutes of flying time) from U.S. or allied shores—not enough time for our radars to track the missiles, much less shoot them.
The satellite shoot-down, as well as some previous testing, suggests that the missile-defense system, once it's installed, might be able to shoot down a) one decoy-less missile b) fired from a distant, known site c) along an arc within range of our radars and interceptors.
This is not to be trivialized. However, we have to assume that we're facing a thinking enemy. It is probably true that some prospective foes—say, North Koreans, Iranians, or Chinese—were very impressed by the satellite shoot-down. They may well have inferred, more than Gen. Cartwright said is justified, that the United States could really soon possess a working anti-missile weapon.
But what will they do in response? Will they see they can't win and fold their cards, shut down their programs to develop nuclear weapons and ballistic missiles? Or will they redouble their efforts—and, in case of war, resolve to fire more missiles than they'd planned to fire—in order to evade or saturate the U.S. defenses? Another way to pose the problem: What would we do, faced with a similar obstacle? The question answers itself.
Another course a thinking enemy might follow is simply not to play our game. For instance, rather than develop ballistic missiles, they might build cruise missiles—which fly through the atmosphere rather than arc into outer space. They are also cheaper and easier to build. And our very expensive ballistic-missile-defense system—on which we've been spending more than $10 billion a year for as long as George W. Bush has been president—has no way of shooting them down.
All this raises a more basic question: Who is this enemy? Officials who justify the missile-defense program warn of "rogue states," like North Korea and Iran, which have active programs to build missiles and, possibly, nuclear weapons. Or they cite the dangers of a terrorist organization, like al-Qaida, somehow acquiring a pocketful of nukes. Against these kinds of foes, a U.S. ballistic-missile-defense system—whether or not it's effective—will tend to push them toward other ways to attack us.
The smart way to play an arms race is to develop weapons that force the enemy to spend more money to counter them. A ballistic-missile-defense system pushes the enemy toward alternatives that cost less.
The other enemy that officials ponder—though they don't mention it very often—is China. They don't mention China very often because it doesn't really pose a threat right now. But if the Chinese did start to flex their muscles and build a truly expansive military force—a force that could project power beyond the Taiwan Strait—they could easily evade and saturate a defensive system. One lesson that everyone—even, eventually, Richard Nixon—learned during the heyday of the Soviet-American arms race was that offense easily beats defense. (This is why both sides signed the Anti-Ballistic-Missile Treaty in 1972. It had nothing to do with the doctrine of "mutual assured destruction"; it stemmed from the realization of strategic futility.)
There are two threats that do exist and that a missile-defense system might be able to handle: a North Korean missile attack against Japan and a Chinese attack against Taiwan. And yet—as John Pike of the invaluable GlobalSecurity.org calculates—the U.S. missile-defense program is not geared toward either of these threats. There are not enough interceptors, nor are they deployed in the right places, to deal with either scenario. Members of Congress might want to ask why not.
There is another oft-cited scenario: a single nuclear-tipped missile launched either by accident or by a lunatic. A missile-defense system might be able to shoot down that missile—if the interceptors are in the right place and if the system is on high alert. How much do we want to spend for such a contingency? This is another question that Congress should debate, if it decides to start debating military strategy or defense budgets ever again.