The North Korea v South Korea hypothetical war is a war that's never going to happen.
Why? Because it just can't be allowed to happen on all sides.
You've got Kim Jong Il up there in the starving North surrounded by his cult of personality, polishing off a bottle of Hennessy every night in his palatial mansion while surfing porn on the only non cock blocked internet in North Korea. His health is fucked and he's about to hand the gravy train off to one of his sons. He picked the youngest one because he's the least retarded and therefore the least likely to start a war with the South and, by doing so, remove the entire "Kim" family from the human genepool. The North has a huge army but shit equipment and a shit airforce. All they have is a shitload of brainwashed youngmen that they could toss into the ring as human wave attacks like the Red Army did against the Germans in 1941. Result: 3 million casualties for nothing.
In the South, they've got a rich 'democracy' (are there any real democracies in the world today?) well aware that its capital is in artillery range of their nutty brother. They get a little touchy about this. South Korea is like some famous movie star who has this awkward little brother who has a habit of masturbating in public and ruining famous older brother's credibility. You can slap him around for doing it but that'll just cause you even more trouble for child abuse. Your only choice is to sit there and enjoy your prosperity and accept the fact that your brother jizzes on you every so often.
Also, the US has thirty thousand troops in the DMZ, so any conflict here will draw in the US which supplies/allows North Korea heating oil and rice in exchange for them not pulling their dick out of their pants.
Still more, China, that country with 1.3 billion people and who bought more new automobiles than the US last year, well, you see, they use North Korea as a buffer zone on the Asian peninsula against encroaching capitalism. LOL seriously! China slaps the shit out of Kim Jong anytime he gets 'ronery' and tries shit with the South because they have no interest in anything that draws the Americans onto the Asian mainland anymoreso than they are already. (Japan, Afghanistan, trade/oil deals with the other 'stans south and west of the Himalayas)
China is run by savvy engineers who know that the only way to win the global chess game is to win structurally and economically. They view the Americans as trigger happy dumbfucks with a big navy, nukes and no money. Having no money makes Americans mad. China would prefer to keep quiet about it, not say anything about the precarious fiscal situation and allow America to destroy itself all by itself which is a pretty good bet if you're Chinese and watch US reality TV.
So put down the popcorn, there is never gonna be a war on the Korean peninsula because big guys behind the scenes have too much to lose.