FIRST came pre-emption, President Bush's declaration that the age of containment was over and that the United States would no longer wait before wiping out potential threats. Now, after he turned doctrine into practice in Iraq, comes the next phase of the strategy: a bid to pre-empt conflict itself by hobbling the traffic in the most horrific armaments.
Call it pre-emptive pre-emption. The aim is to keep countries like North Korea, Iran, Libya and Syria from trading in arms that could be slipped to terrorists or used to challenge American power.
Under this new approach, now being refined by Pentagon and State Department officials, the White House is pressing for a coalition of nations that would allow ships to be boarded and aircraft to be forced down the moment they slipped into any cooperative country's waters or airspace. Thus the United States and its allies would combine intelligence with creative use of national laws to seize suspicious shipments around the world and disrupt the transportation system for everything from missiles to the centrifuges used to enrich uranium.
As Mr. Bush headed to his parents' house here on Thursday, American officials and many of their allies were meeting in Spain to devise the new rules. Britain, France, Germany, Australia, Poland and Japan were represented, but not Russia, China and South Korea. The next day, in a sign of why the United States believes it needs to move fast, the Thai police seized 60 pounds of radioactive cesium in Bangkok that authorities believe may have been intended for use in ''dirty bombs.''
The administration's initiative was born partly out of frustration with the way international law had deep-sixed an effort to stop the shipment of North Korean missiles to Yemen last year. Rather than try to rewrite international laws that govern freedom of the seas -- bedrock principles for the global economy and American economic power -- the White House decided to base its efforts on the inventive use of national laws.
Some experts said the strategy of stepping up pressure on North Korea and other countries without creating international legal problems is creative, if complicated. ''It requires a lot of cooperation -- the Chinese, for example -- and an agreement on what constitutes contraband,'' said Michael E. O'Hanlon, a scholar at the Brookings Institution who has studied the implications of the Bush approach.