Here's a sensible, sane editorial on North Korea, from the Economist.

On cutting deals with North Korea and trusting them:

The biggest difficulty is Mr Kim's serial promise-breaking. His first shot at plutonium-making back in the early 1990s had already broken both the NPT and a North-South agreement to keep the peninsula nuclear-free. His recently discovered uranium enriching, and his claimed resumption of plutonium reprocessing, have in effect consigned these agreements and his 1994 one with America to the shredder. How could anyone be sure he would honour a new one?

Good question. Short answer: You can't. They suggest, as I have, intrusive inspections. But it is reasonable to argue that inspections will never work without the cooperation of the state being inspected.

The editorial lays out the relevant issues well, but skirts around consequences.

And if Mr Kim drags his feet and hangs on to his weapons? Then he should be told to expect isolation and containment. Though it has no interest in seeing a nuclear North Korea, China has always balked at sanctions (and South Korea and Japan have never been keen). Yet the stakes this time are explosive. China has already put aside past indifference and joined the talks with America and North Korea. Some say it flicked off the oil taps earlier this year to get the recalcitrant Mr Kim's attention. But it may have to get tougher yet.

Okay, but North Korea has openly said that sanctions would be considered an act of war. And as with inspections, there are very good arguments to be made that sanctions are a horrible tool for coercion, punishing the innocent while not really hurting the regimes you're trying to change, perhaps even moreso than war.