Why ever should North Korea be scared or upset about the world scolding it for killing more South Korean soldiers and bombing South Korean territory? The world stood back and used very strongly-worded missives to deliver harsh rebukes when the North blew one of the South's ships out of the water earlier this year.
The U.S. isn't really out of Iraq yet, not talking about getting out of Afghanistan until 2013, broke, and weary from the longest period of continuous war in our country's history. The Europeans have no stomach for a land war in Asia. China is slowly becoming aware, as Japan has been for some time now, that it too can be a target and its ill-behaved client is bad for business. But unlike anyone else on the stage, China is possessed of a credible ability, coupled with the will, to wipe Pyongyang off the map. An overt, all-out attack on the South would be counterproductive in that the South is its primary source of material necessary for survival; it, in turn, can devote all of its economic abilities to making guns since with those guns, it is able to extort butter from the rest of the world.
So the North Korean leadership can, within its sphere of influence, do what it pleases and say, "What are you going to do about it, bitches? Say 'stop' again?" And we'll react the way we always have -- which is to give in to their strategy, up the food imports and foreign aid, and mutter about the extortion to ourselves -- since downtown Seoul is located within howitzer range of the DMZ and we aren't really sure yet whether they have nukes or not or if they are really crazy enough to use them.
What incentive can we give them to rejoin the civilized world and stop being the bully over in the corner of the yard demanding that the rest of us cough up our lunch money?