On Saturday, North Korea declared an intention to continue to develop nuclear weapons and announced the existence of a parallel program to enrich uranium for use in weapons.
The suspected existence of the uranium program helped derail the Agreed Framework that held between 1994 and 2002 (U.S. intransigence also helped), which eventually led to the restart of the plutonium program at Yongbyon. To be clear, the North Koreans have claimed that they will commence a uranium enrichment program, rather than acknowledging that one has existed all along. The North Korean declaration is in response to the tighter sanctions regime established by Friday's UN Security Council resolution, which provided legal justification for UN member states to intercept and inspect North Korean vessels suspected of carrying weapons. It also looks as if North Korea may be preparing a third nuclear test; the general consensus is now that the device in the first test failed completely and the device in the second failed partially. North Korea is suspected to have enough plutonium for about half a dozen bombs, but I haven't seen a good estimate of how much uranium it could have enriched.
Galrahn has a brief discussion of what the UN resolution means. China and Russia have committed, in word if not yet in action, to a regime that allows the interception and inspection of North Korean ships carrying prohibited weapons. The important caveat is that the resolution simply recommends interception of suspected cargoes, rather than mandating it. But the resolution also bars North Korea from exporting any arms at all (and from importing most arms), which is fairly wide-ranging authority. Even if China and Russia aren't fully on board with implementation, the resolution makes any effort to export very risky for the North Koreans. Potential buyers of North Korean arms are far away, and any ship carrying arms would run the risk of interception in various ports of call.
All of this seems to me to be the right way to go. It's fair enough to suggest that we should tread lightly where North Korea is concerned, but that doesn't obviate the international community of the responsibility to establish boundaries of appropriate conduct. North Korean breaches of these lines have made China, Russia, and South Korea more willing to engage in assertive diplomatic action than they had previously been prepared for. If additional tests are simply a negotiating tactic on the part of the North Koreans, then additional UN sanctions are the diplomatic counter-tactic of the U.S., Russia, China, and South Korea.
I'm not too worried about additional North Korean nuclear tests (each test expends plutonium while unifying the international community), but the concern is that the next negotiating tactic the North Koreans will employ will involve military skirmishes along the demilitarized zone, or near offshore islands.
The proximate cause of the latest North Korean intransigence may be a succession crisis; Kim Jong-Il is known to be in poor health, and South Korean reports indicate that his youngest son, Kim Jong-un, has been designated successor. No one knows quite what this means. The best we can say is that both known unknowns and unknown unknowns remain plentiful on North Korea.
--Robert Farley