It's not the technology. We already possess the scientific know-how to hit a "bullet with a bullet," as the recent successful test above the Pacific showed. And this feat is hardly new: The Army's "theater" missile-defense system, designed to protect U.S. troops against medium-range ballistic missiles, has had several successful intercepts since 1997. The challenge has always been how to do the same thing on a larger scale.
And the problem is not the opposition from Russia and some of our European allies. Yes, we still hear dark mutterings from some leaders about how "destabilizing" a U.S. missile-defense system would be (as if the missile programs in North Korea, Iran and Iraq haven't been destabilizing). But most leaders now appear amenable, even if they're not enthusiastic.
Russian leaders also have signaled their acceptance, however grudgingly, asking only that a U.S. missile defense be tied to deep cuts in our respective nuclear arsenals.
The big obstacle is none of the above. It's our continued adherence to a 29-year-old agreement revered by arms-control advocates as the Holy of Holies: the Anti-Ballistic Missile (ABM) Treaty.
Why? Because it forbids its signers -- the United States and the Soviet Union -- from deploying a national missile defense.
Indeed, under the treaty, we cannot even test many of the most promising technologies available. Article V states that "each party undertakes not to develop, test, or deploy ABM systems or components which are sea-based, air-based, space-based, or mobile land-based." That doesn't leave many options.
About all it does leave is the fixed, ground-based system we've been testing over the last few years, even though most experts believe a sea- and space-based defense -- one that can target missiles early in their flight path, during their slow-moving "boost" phase -- is a better way to go.
The fact is, as long as the ABM Treaty is considered in force, any effort to build the most effective missile-defense system possible is compromised.
Fortunately, President Bush has said he's committed to "move beyond" the ABM Treaty. Deputy Secretary of State Paul Wolfowitz calls it "obsolete" and admits the administration's activities on missile defense will "bump up against" the treaty in a matter of "months rather than years."
By proposing a "layered" system of land, sea and space components -- which would provide the best possible defense -- the administration has confronted the dark truth: that you can't have both the 1972 treaty and an effective protection.
So the president should now state the obvious and declare that the United States is withdrawing from the ABM Treaty.
It's like a missile-defense test: You can do a hundred things right, but one wrong thing can cause you to miss by a mile. And the one wrong thing we can do now is give arms-control proponents reason to believe the treaty can somehow be salvaged. The New York Times recently suggested it could be "modified." But this is like offering to loosen a pair of handcuffs. Until we formally pull out of the treaty, we're encouraging this view.
We're also giving congressional opponents of missile defense excuses to throw roadblocks in its way. Some lawmakers have said they plan to cut money from defense programs that threaten to conflict with the ABM Treaty. They want to reduce the $8.3 billion the Bush administration has requested for missile defense -- a pittance compared to the total U.S. defense budget of more than $329 billion -- by an additional $1.2 billion.
Deliberate ambiguity is sometimes necessary in diplomacy. But on missile defense, it's not serving us well. We risk emboldening opponents on both sides of the Atlantic, who still cling to the misguided notion that we can have a limited missile defense and a modified ABM Treaty. We can't. In this instance, ambiguity signals weakness.
Distributed nationally by Knight-Ridder/Tribune News Wire