Part of the reason inaction has happened against North Korea is partly because, who wants to take the time, money, and other resources to help a bunch of starving illiterate brainwashed peasants? That sounds cruel, but someone would have to take the initiative, donate much of their countries resources, all just to raise the standard of living in North Korea to post-dark age Europe. That being said, they know that the fight would be laughably one sided, they aren't stupid. What I don't know is whether or not North Korea has the self preservation 'instinct' that other countries or cultures have. During Desert Storm, America hit the Iraqi's so hard and fast that the standard troops gave up when given the opportunity. That's partly why I'm not as worried about Iran, who seem to adhere to that policy.