Here is an interesting opinion on N. Korea ... and I think is likely correct.
Rather than behaving in such suicidal fashion, Kim could be thinking more creatively about the strategic utility of his small nuclear arsenal across the spectrum of bad behavior open to him. The simplest and safest path he can pursue is to persist in his bluster while refraining from any kind of serious military provocation. When the current furore dies down, he can declare victory in this latest confrontation. Or, ratcheting up the action just a little, he might order something like the 2010 artillery bombardment of the border island Yeongpyeong, during which some South Korean soldiers were killed. Both large-scale bluster and small-scale bombardment are more than adequately supportable by the North's nuclear capacities. Nobody is going to war against Pyongyang on the basis of harsh rhetoric or mild skirmishing. So stand by for more churlishness, and maybe even a little violence.
http://www.foreignpolicy.com/articles/2013/04/08/rolling_the_iron_dice?wp_login_redirect=0