In a much-needed clarification of his administration’s intentions for an anti-missile system to protect the nation from attack, President George W. Bush last week outlined what he termed a “new framework” for countering missile threats from so-called rogue nations and accidental launches. The latest plan, which is likely to cost far more than the $60 billion estimate made by the Congressional Budget Office under President Bill Clinton, contravenes the 1972 Anti-Ballistic Missile (ABM) Treaty with Russia. In addition, the new policy questions whether the policy of “mutually assured destruction,” which has guided American nuclear policy for so long, still applies in a world with many nuclear powers. Although the president’s overtures to Russia—who is eager to have a stake in any defense strategy lest its rusting arsenal become irrelevant—is laudable, his planned abrogation of the 1972 treaty is both alarming and provocative. An even greater worry is Bush’s unconcern for the Chinese reaction to his missile defense plans. And we doubt Bush’s assurances that a large-scale missile defense is technologically possible without breaking the bank.

Bush reasons that the world has changed since the 1972 treaty was signed. The treaty had relied for deterrence on the absence of missile defenses—and thus a guarantee of mutual destruction after any first strike—to keep the peace between the U.S. and the Soviet Union. But in an age when dictators like Saddam Hussein could obtain nuclear weapons, a rogue state could launch an attack and might just be crazy enough to accept the horrible consequences. Bush’s arguments on those grounds, however, fall flat. Most terrorists or rogue states lack the missile capacity to attack the United States and would most likely sneak nuclear, chemical or biological weapons into the U.S. through other means—say, a suitcase in a commercial plane. It is unlikely that a nation such as Iraq, Iran or North Korea would develop and launch a ballistic missile when much less-challenging and easier-to-conceal methods are available.

The focus on missile defenses has also raised significant dangers due to the near-total exclusion of China from the negotiations surrounding the plan. China has been left out of the continuing talks between Washington and Moscow about how the defense system will be structured. In a speech at the National Defense University last Tuesday, Bush stressed the importance of building a relationship between Russia and the U.S., but China, which is important for both military and economic reasons, was ignored.

China is one of the most likely targets for the defenses that Bush has proposed, as its small arsenal of nuclear warheads could be nearly completely countered. Russia’s arsenal is far too vast to be defended against, but China—which would fear an American first strike without the ability to retaliate—would have a strong incentive to build up its arsenal in order to overwhelm the defenses. A renewed arms buildup could be severely destabilizing, and leaving China out of this process only courts further tension.

Given the abysmal record of the current testing of the American anti-missile system. the best defense against missile attacks would therefore be the small, local shields that are explicitly allowed under the 1972 treaty. Such shields would be able to guard against a few missiles from terrorists or rogue states but could not be used against an arsenal such as China’s. But they would not require immense expenditures and have a far higher chance of producing a working, reliable defense for Americans.

Bush’s overtures towards unilateral reductions in nuclear weapons are heartening, but the missile defense scheme he has proposed is unworkable and diplomatically dangerous. The 1995 nerve gas attack on a Japanese subway was a warning that the most serious threats to the U.S. in the future will come from terrorists who are unlikely to play by the old rules of military engagement. The president should concentrate on such smaller-scale and regional defenses before playing a needless game of nuclear politics.