Although most South Korean doesn't much worry about full scale war with north, it's quite true that there is a possibility of small scale conflict.

Why? If you hate my guts, why should I put my neck on the line for you? If we work in the same office, I help you out and cover for you but you spread rumors about me behind my back, you're on your own

If we're making simple analogies -
It's more like: your friend owns a factory that cooperates with your own factory, for the profit of you both. Some of his workers don't like you (because they saw you kill a hooker that one time), so you burn his factory.

Let me help:

your friend owns a factory that cooperates with your own factory, for the profit of you both, but your friend makes a higher profit. Some of his workers don't like you (because they saw you kill a hooker that one time), so you end the business deal and let him find a new business parter.

SK is a US ally?

Yes, in verbal, economic, military, social, political, and legal contract-wise sense, South Korea is one of our most important allies in Asia. The only other one that is a closer ally is Japan.

What makes you think that SK and US are -- in any way -- good buddies?

The immense friendship that exists between South Korea and the United States has existed for several decades now and is well documented.

We're closer friends with South Korea than we are with Mexico. And we're next door neighbors with Mexico. Actually, we don't get along too well with Mexico.
We probably are as good buds with the S. Koreans as we are with the British. Koreans are awesome, and we have staggeringly great relationships with the Southern portion of that peninsula.

I live in the midwest, and though it's partly because of the nature of the social circles I move in, I've had more contact than Koreans than any other foreign ethnicity, and they have always been friendly towards us Americans, and us Americans have always held them in positive light. Every South Korean I've met (and again, I've met alot, from many social classes) have honor and integrity, and are polite and humble as well.

The last thing the United States needs, is to show the entire world that we'll pull out of friendly nations, just because unfriendly nations start rattling their sabers.

The unfriendly nations will always rattle. But SK is a friendly nation? Since when?

Since we rescued them from the Japanese Empire during WW2, and gave them their independence again (which was forcibly taken), and since they stood with us during the Cold War, and since we came to their rescue in the Korean War. Had they became communists (and sided against us), they wouldn't have needed us to come rescue them. But they chose to stand with us (because of us giving them independence from Japan), so we have had the honor to stand with them when they were invaded by North Korea and then China. This is history. Our alliance and friendship with them has been signed with blood - our blood and theirs.

You, who were born less than thirty years ago, may not have know this. But our two nations have a tie that is very strong, and for you to pretend it doesn't exist is pretty silly.

I urge you to re-read my initial post about SK and note the rising anti-Americanism in the country. The better question to ask is: Why help countries that hate you?

A) They don't hate us. They are one of the few nations that actually like us.
B) Our entire power and influence as the United States has come from our helping nations that hated us. Again, Japan is one of our closest allies. They became our ally because we rebuilt their nation, boosted their economy, and vowed to (guess what!) militarily defend them, after we nuked their cities and won the war and disarmed them.

If you are going to play with our foreign policy, at least recognize how we became as powerful as we did.

All of Asia doesn't hate us. Just North Korea, and parts of China.
Taiwan, Japan, and South Korea, are friendly towards us. And soon even Vietnam will become more friendly. We recently started rebuilding political ties with them (which they have been very receptive of), to repair the damage done by our invasion of them during Vietnam.

The Koreas, Vietnam, Taiwan, and Japan would lose most of their national freedom.

Well, the Koreas don't like us as it is and since they're adults, they can deal with their problems.

They do like us. All of our history says it. My personal experience with the Koreans say it. The rest of the world says it.
Their problem was created by us when the South Koreans backed us during the Cold War. It's our problem too, and our nations are heavily tied economically, militarily, and socially. We're friends, whether you know it or not.

As for the assumption that Taiwan and Japan will be invaded or taken over somehow by China, that's a pretty absurd jump in logic and holds more than a train-load of assumptions. How does leaving SK to fend for itself automatically have China landing troops in Japan and Taiwan?

I'm not worried about China militarily invading (at least not in the next twenty years). But if the United States pulls out of the Pacific Zone, China can bully Japan and the other nearby nations moreso than they've already started doing. To pull out of South Korea militarily - despite our public and world-recognized (except by you) commitments to defend South Korea - we basically take our influence in that entire sphere of the world from an '8' to a '2' overnight.

China, by the way, still considers Taiwan as stolen Chinese territory. Taiwan is the non-communist government of China that was exiled from China when the communists took over. China doesn't recognize them as an entity, and has been waiting for ages to get it back. The ultimate sign of China as a super-power will be the reclaimation of Taiwan. Taiwan is officially know as "The Republic of China".
Again, this is history. And it's not very old history either! We're not talking about events that occurred back in the times of the Romans, which would be understandable if you weren't aware of, we're talking about events that happened practically last month when it comes to lifespan of nations.

If I say I'm going to back you, I should try to back you, even if it comes at my expense.

You can do that. And that would be a foolish thing to do. When you have one group of people helping/defending another that actively hate their benefactors, then the former deserve anything bad that might happen to them.

First, they don't hate us. You're wrong about that.

Second, integrity that fades under pressure is not integrity at all - and those who backstab their allies get backstabbed themselves. If we abadon South Korea, I bet China (weary of North Korea's antics), would secretly egg on North Korea and then come to South Korea's rescue, unify them both under South Korea, and win South Korea as an major ally... one who would hate us for abandoning them when push comes to shove.

"Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful."

Actually, you've indadvertedly stepped at the heart of this issue: continued US support for SK -- given its anti-American position and stance in society and government -- is just plain stupid.

I haven't "inadvertently" stepped anywhere, anymore than the United States "inadvertently" supports South Korea. It's in our interests to! Economically, politically, and militarily (Also religiously - there is a major religious alliance between our two nations also, but you're neither aware of, or care about, that).

American foreign policy is downright idiotic to support this government after it has thrown dirt in the face of Uncle Sam.

Again, our power as a nation has come predominantly because of our foreign policy. We've found (accurately!) that we spend less money and gain more power if we financially support other nations (either as allies, or even as enemies) than it is to go to war with them.

We've thrown more dirt in the faces of our allies than our allies has thrown at us. South Koreans have literally died for us. And Americans have literally died for them. Both our nations have found, and history has proven this true, that both of our nations benefit by our military agreements.

Long-term, we'll hurt worse if we back down - unless you want North Korea to continue developing nuclear weapons, and then sell them to all the nations who hate us.

They've done that already. So what's the concern further?

Their nukes right now are a joke. The fact that they have them isn't a joke, but they aren't yet usable in any real way. By continuing to refine their nukes, they - the nukes, not the nation - will become a very real threat to us. The nation will never become a threat to us, but by selling nukes to our other enemies in the Middle East, both the governments and the guerillas, they can do us some real damage.

If I have a vote, I'd say send in the Marines. And soon. Unify the Korean peninsula under South Korea, and we'll strengthen our biggest asset in the Asian hemisphere. The only thing is, we'd have to figure out some way of military action in North Korea without ticking off China, which is the real (and only) problem.

You know, I'd love to believe that, I really would. But you're making a lot of assumptions:
1 - NK has a reliable and accurate nuclear weapons delivery platform. Their rockets are a step above SCUDs.
2 - Their nukes are reliable to detonate when they need to. No evidence of this to date.
3 - They actively want war that could topple their regime or at least make them puppets of Beijing.

Just to be clear about those points:

1 - You don't need reliable and accurate rockets that hit on target 5,000 km away. It is perfectly possible to fire them off a submarine less than 100km from the coast. In fact, this is much preferrable, since this prevails counter-measures and doesn't allow people to seek shelter. Also, even a SCUD will reliably hit at a NK-Japan or a NK-SK distance. Given the high population density in that region, it doesn't matter much what you hit either, you always hit something and someone.

2 - Nukes not reliable to detonate are not an issue. Building a nuke is dead simple. I could build a nuke that is reliable to detonate in my garage, provided a few simple to obtain (... simple for a country's government) materials. The true difficulty in building a nuke is not to make it detonate reliably, but to prevent unauthorized persons from detonating it.

3 - That is partly US propaganda, partly true. For the most part, Kim is reacting to an US provocation (which makes his threats somewhat justifiable). But sure, he is probably crazy enough to want war anyway. However, is he convinced that it will overthrow his regime? Think again, a war is not only led with nuclear weapons, and not between two isolated parties.

While it's true that the average man in NK does not have access to internet, nevertheless some of the nastiest cybercriminals come from there (rivalled only by China and Russia). It is very conceivable to start a war with a massive government-supported cyber-attack which may very well bring down a country like the USA (or nearly so). Remember that everything, really everything, from electricity to civil order, depends on computers and computer networks in the US. They need not even smuggle saboteurs into the country thanks to the internet (though they could as well play the old spy-vs-spy game, if you choose when war starts, you have years to prepare). Luckily, all vital computer systems in the USA are unhackable, thank God.

And then consider that pretty much everybody hates the USA, not just North Korea. Al Quaida has been very quiet of late, did you wonder why? Think they give up? Unlikely.

It is more likely that they are preparing, placing sleepers, and waiting for a good opportunity. It is not entirely impossible that Al Quaida will "help" Kim with a few well-placed terror strikes the moment war breaks out. My enemy's enemy is my ally, you know.

Or, for example, Iran (who has nukes, too) might use the opportunity to get rid of Israel while everyone is looking towards the far east.

And suddenly, situation isn't all black and white any more. It is not that clear who will "win".