The recent tsunami in Japan made it possible to measure the antineutrinos coming from inside Earth. Read article here. This is a fascinating story in itself, 38% of the energy fueling plate tectonics, and the Earth's magnetic field, comes from radioactivity in the Earth's interior, nevertheless I write here about the North Korean Nuclear Threat.
Reading the article above, I realized that South Korea uses a considerable amount of nuclear technology. To my unschooled mind, I do not see differences between the North and South Koreans. They share History, and a small Demilitarized Zone. It stands to reason that the North can pose a Nuclear Threat.
You don't need a weatherman to know which way the wind blows!