What is the US able to do about N Korea's Kim?

In short, this would take away Kim's favorite tactic, which is brinkmanship.

The ripple-out effect of the North Korean detonation will take some weeks to become clear. China has surely lost face because of the failure of the six- party talks that Beijing initiated. South Korea is in a quandary as Seoul's policy of appeasing North Korea has failed.

Tokyo, on the other hand, has acted decisively in line with its newly assertive international posture, banning North Koreans, North Korean ships, and North Korean goods from entering Japan.

Moreover, it seems likely that the Japanese will seek to tighten their alliance with the US.

A great unknown is the effect on Iran, which is seeking to be the next nation to cross the nuclear threshold. The campaign against nuclear proliferation has been weakened but how much is a question mark.

Richard Halloran is a writer based in Hawaii.