Thanks

North Korea is making a lot of noise, but tensions rise and fall on the Korean peninsula like a heart beat. Over the last several decades, the north has launched special forces and assassination attempts against the south and even taken a US warship hostage. What's happening now seems to be directed towards the North Korean population as part of the preparation for regime change. The US is also a target audience, since the current administration has taken a fairly hard line towards negotiations with North Korea. North Korea is supported totally by foreign energy and food aid. Maintaining that support is vital to the regime.

I'm not particularly concerned about the latest nuclear test (I am broadly concerned about the continued spread of nuclear weapon technology). The test is a message, part of negotiation. It was even announced a few months ago. North Korea is talking, I think about it as national body language.