Even if the NK nuke was a dud...

Counterproliferation remains one of the great foreign policy challenges of our time.

The Christian Science Monitor:

"Now is the time for farsighted, collaborative, and smart policies to prevent the further spread and use of nuclear weapons," concludes George Perkovich, a nuclear strategy and nonproliferation expert at the Carnegie Endowment for International Peace in Washington.

[...]

As US officials noted, even North Korea's claim that it had exploded a nuclear device represented the crossing of a fateful threshold. If nothing else, Pyongyang had called Washington's bluff, some experts pointed out. President Bush, among others, has said in the past that the US would not "tolerate" an overtly nuclear North Korea.

Given the military difficulties of attacking a nuclear-weapon state, and of destroying stockpiles of fissile material, "tolerate" may no longer be the operative word.

"Any US statements that North Korea cannot be allowed to acquire nuclear weapons are meaningless bluster," writes Anthony Cordesman, a military expert at the Center for Strategic and International Studies, in an analysis of the meaning of the North Korean test.

At the same time, the test shows that current US policies aimed at curbing North Korea's nuclear ambitions haven't worked, says Daryl Kimball, executive director of the Arms Control Association in Washington. A new, more energetic diplomatic approach is needed - and fast, he says.