Allison was touching on the central dilemma facing Washington as it tries to extract itself from the morass of Iraq. Whether accurately or not, other countries around the world perceive Washington as tied down, unable or unwilling to challenge them while 140,000 troops are trying to tame a sectarian war.

Divining North Korea's true intentions is always difficult; there is no more closed society on earth. But the broad assumption inside and outside the United States government is that Kim's first priority is the survival of his government. And the second is that without a nuclear weapon, he believes his government would have no way of staving off the larger, richer powers around it: China, Japan, South Korea and the United States.

All have fought over control of the Korean Peninsula in decades past, and to Kim's mind, presumably, the prospect that the North could lash out is the only reason they have stayed at bay.

Kim may have calculated, many experts believe, that at this point there is little more that the Bush administration can do to him. The United States has imposed sanctions on his country since the end of the Korean War. The new crackdown on the banks through which the North conducts many of its illicit activities — counterfeiting, missile sales, trade in small arms — are being choked off, a step the North Korean leaders presumably see as part of a strategy of bringing them down.

It may be years, or decades, before historians know whether Iraq played into Kim's calculations about when to conduct a nuclear test. But clearly, managing simultaneous crises around the world is straining the system in Washington, and posing the Bush administration with more direct challenges than many believe it can handle at one moment.

That returns Bush to the problem he faced when he came to office, and that his aides have never stopped arguing about: Whether the best way to contain North Korea is to further isolate it, or to draw it out of its paranoid shell. The nuclear test may force Washington to pick a strategy.