INDEFENSIBLE.(The Talk of the Town)

In July, the first interceptor for a national missile-defense system was installed at Fort Greely, Alaska. A few weeks later, President Bush announced that the first components of that system would soon "become operational." Speaking at a Boeing aerospace plant in Ridley Park, Pennsylvania, on August 17th, he praised the efforts of those who are making the deployment possible, and declared, "We say to those tyrants who believe they can blackmail America and the free world, 'You fire, we're going to shoot it down.' " It will come as a surprise to Americans and tyrants alike that the controversial system is ready to shoot anything down--not much has been heard about it since the attacks of September 11, 2001, redefined the national notion of defense. Yet Bush promised to develop the system in his last campaign, and in December, 2002, a year after the Administration announced that it would withdraw from the Anti-Ballistic Missile Treaty, he ordered that deployment take place in 2004. The due date became October 1st.

For the past three years, officials at the Missile Defense Agency have worked overtime to create a system that they say will neutralize a missile threat from North Korea. In collaboration with Orbital and other contractors, they have built a new three-stage booster rocket and "kill vehicle" for the interceptor. They have built a seven-hundred-acre missile field at Fort Greely, and modified four silos at Vandenberg Air Force Base, in California. They have laid a thirteen-thousand-mile-long fibre-optic cable linking Washington, D.C., to Fort Greely, several sites in California, and the U.S. Northern Command, at Cheyenne Mountain, Colorado. At a site in Corpus Christi, Texas, they are constructing a sophisticated radar that will be mobile and seaborne. Twenty-five stories high and weighing fifty thousand tons, the radar will be installed on a self-propelled oil platform, and, because it is too big to fit through the Panama Canal, it will have to sail around Cape Horn on its way up to the Aleutian Islands, dodging gales from the Bering Sea.

Still, despite all this effort, the deployment will be much less than complete. As envisaged by the Bush Administration, the system is to eventually include two satellites (one in high orbit, one in low) to assist in the early detection of missile launches, track missiles, and help guide interceptors to their targets. Both satellites have fallen years behind schedule, however, so, until the new radar arrives, the interceptors will have to rely in large part on radar systems that were developed in the nineteensixties and seventies to provide early warning of Soviet missile launches. The most important system, in the Aleutians, has not been tested for its new role, and, because of the way it is positioned, it would not be able to detect a North Korean launch aimed at Hawaii. Ten interceptors were scheduled to be in place, but, by the time of deployment, there will be at most five or six, and no one knows whether they can hit anything, because they have not yet been tested against targets.

Between 1999 and December, 2002, a prototype anti-missile interceptor did succeed five times out of eight in hitting a dummy warhead in space. However, it was given information that the North Koreans would be unlikely to provide, such as the time and place of the launch and the missile's trajectory. Moreover, the tests were purely preliminary. They did not show whether the system would work at night, or in bad ...