Move the 30,000 US troops away from the DMZ. Give NK a warning, and follow up with the Chinese.
The next time they light one off, destroy the launch sites and keep a couple of carriers, some submarines and some air resources on station.
Arm the Japanese.
Those 30,000 U.S. troops are essential to keep South Korea from being over run by the hordes of North Korean troops. Plus, we are technically still at war with North Korea and will be seen as a sign of weakness by the North Koreans if they are removed. We must show to the world that we are willing to kick some North Korean butt all the way to the Yalu River.
I hate to tell you this but bombing the launch sites is asinine and something only a Clintonoid would recommend. You bomb them before they get nukes not afterwords. Go back to DU.
Arm the Japanese? The Self-Defense Force is small, but just about the only military in the world that's up to US standards (some element of the UK's forces aside). I guess you missed the remark by a recent Japanese Defense Minister, "If on Monday Japan decides it needs nuclear weapons, by Friday it will have them."
Given that the Japanese Atomic Energy agency has 20 of the world's 100 largest supercomputers, and that you don't need supercomputers to design or run nuclear power plants, but you do need them to test nuclear weapons designs without actually setting one off, it sound to me like Japan already has a few 'non-bombs' that can be turned into nuclear bombs by turning a few screws.
For the peace of the world, we must hope the remark and the import of the Japanese supercomputers is not lost on Kim Jong-Il.