The North Koreans aren't alone in this, either. Both they and mainland China, Taiwan to some extent, and other East Asian nations are big on the rhetoric, and the threats. Part of the ruse is posturing, attempting to establish a strong and unwavering position from which to negotiate. Part of it appears to me to be an attempt by the table-banger to outline the very shortest path to disaster. Usually, in my limited and inexpert observation, the "threat" is a hypothetical response to some stated anticipated move by other nations.
The important thing to remember is that all this tension-ratcheting and posturing has about as little to do with actual nuclear weapons as a six-year old playing in a sandbox has to do with them. There are credible rumors which suggest that NK's first test wasn't a nuclear weapon at all. There are half a dozen nations out there that may wish to wreck a North Korean missile launch simply to test their own anti-missile systems and espionage capability. North Korea's largest actual threat is the ability to dump a million artillery shells an hour into the Seoul metropolitan area--that's the one you
never hear them talk about.
Rather, this current round of stormy weather has to do with averting yet another famine in North Korea, which is too corrupt to feed itself, and with guaranteeing the territorial and political integrity of the Kim family tyranny as it transitions to yet another insane redneck dictator. North Korea ratchets up the tension and attempts to bargain away the tension in return for aid and stability. South Korea usually reaps its own rewards at the same time. The tactic has been a resounding success for both nations since the death of Kim Ill Sung, perhaps long before that.
Edit: I should provide an example to demonstrate what I mean in the last sentence of my first paragraph, easily found in today's news:
"
If the U.S. imperialists start another war, the army and people of Korea will ... wipe out the aggressors on the globe once and for all," a dispatch from the official Korean Central News Agency said.
http://www.huffingtonpost.com/2009/06/24/north-korea-threatens-to-_3_n_220001.htmlAs long as it's an if/then statement, the North Koreans feel free to jump squarely to the worst conclusion. It's scary, but it's not an operative threat, because we're not going to start that war and neither are they. Or so we hope.