Stephen Walt says the US shouldn't take North Korea's nuclear bait:
So the best response is to remain calm, and stop talking as if this event is a test of Obama's resolve or a fundamental challenge to U.S. policy. In fact, the tests are just "business as usual" for North Korea, and it would better if the United States "under-reacts" rather than overreacts. Instead of giving Pyongyang the attention it wants, the United States should use this incident as an opportunity to build consensus among the main interested parties (China, Russia, South Korea, Japan) and let China take the lead in addressing it. Above all, the Obama administration should avoid making a lot of sweeping statements about how it will not "tolerate" a North Korean nuclear capability. The fact is that we've tolerated it for some time now, and since we don't have good options for dealing with it, that's precisely what we will continue to do.