The post-Cold War world is very unstable, as conflicts in the Balkans and on the periphery of the old Soviet Union remind us every day. There are serious problems, nonetheless, with the Bush administration's ABM plans that go beyond the question of whether it could deter a missile attack. That is deterrence of a very high order, and it doesn't require an ABM defense to make it work. Furthermore, advances in weaponry threaten to render an ABM system obsolescent by the time it goes into operation years from now. Cruise missiles fly below ABM radars.
Nuclear bombs are now small enough to be smuggled into the United States.
No ABM system can counter such weapons. Before the Bush administration moves any further on an ABM system, the president and his advisers should lend a full ear to the doubters. There are still too many unanswered questions, both in policy and in technology, to push the ABM pedal to the metal. Act in haste and repent at leisure applies here, too.