After expelling UN nuclear inspectors last month, North Korea seized headlines with its threat to re-start production of fissile materials used to build nuclear bombs. Washington has launched an aggressive diplomatic effort to force Pyongyang to halt its plans, with threats of sanctions should it fail to comply.

One year ago in his State of the Union speech, President Bush labeled North Korea as a member of an "axis of evil" along with Iran and Iraq. Iraq has the weakest military, North Korea the strongest.

Iraq, after admitting UN inspectors, faces an impending U.S.-led war despite no hard evidence it retains weapons of mass destruction. North Korea - which, according to U.S. intelligence, already possesses two to five nuclear weapons - has expelled inspectors and boldly affirmed its nuclear program, yet is dealt dialogue and diplomacy rather than deployment.

The Bush administration has blurred traditional distinctions between preemption and prevention, say critics. They cite apparent inconsistencies in the White House's declared doctrine of preemptive strikes - a policy from which administration officials, including President Bush, are now distancing themselves. U.S. officials may not take their own policy literally, but analysts fear that leaders around the world will take tough talk at face value - and respond in ways that heighten global insecurity and fuel weapons proliferation.

Will preemptive strikes apply only to those too weak to retaliate? How should nations and regimes who possess weapons of mass destruction be handled - is diplomacy in one case and deployment in another a foreign policy double standard? Should a single WMD standard apply equally to all?