Yet I imagine America would be really mad if China moved in on a country directly adjacent to them.

Keep in mind, invading North Korea would cause a massive refugee problem.

It's the same reason Egypt HELPS Israel with their blockade of Palestine despite claiming to be Palestine's ally.

A war in North Korea would be very different from a war in Afghanistan, it would in this case actually be closer to a liberation than an occupation - while the communist state controls the country in a dictatorship the majority of the populous is not communist. Look at the states of the Iron Curtain for a similiar example, they wanted out of communism.

Also for the person saying brinkmanship - you're right but it's one sided brinksmanship. North Korea is being provocative - possibly due to internal politics with the ill health of Kim Jong Il, South Korea isn't being particularly provocative.

China is in a tough position, if North Korea pushes too far they will not have the international political capital to defend N.Korea - they rely on being reasonably friendly with the West for trade. However they really don't want South Korea - a fairly liberal democracy - right on their border, which essentially what will happen if the N.Korean state fails.

It's going to be interesting, it all really depends on what this young man they've essentially chosen for succession is like. If he's as nuts as his father then I can't see N.Korea lasting, it's already bankrupt and starving.

Edit: And invading N.Korea without even more significant provocation than this would be insane. It would need to be a bulletproof and undeniable casus belli. Something like a military attack on a S.Korean city. Something that is so absurdly provocative and undeniable that not even China can justify defending N.Korea.

Don't sleep, we need to save the world!

Its all nice to talk about invading North Korea but as users have pointed out China and even somewhat Russia have ties to North Korea. You would need their support in order to avoid a possible world war. Also North Korea has 3,500,000 soldiers in their army. While poorly equiped that is more then enough brute force to invade and conquer South Korea. Also remember North Korea has thousands of artillery and long range weapons aimed at Seoul and could flatten most major cities over night.

Winning such a war would probubly require the US and even Nato to conscript the majority of their citizens into the army. Losses of millions of lives are probable. Unlike Afghanistan a war in Korea could destabalize the whole earth. While the US and Nato are invading and dealing with North Korea other rogue states like Iran could take advantage of the US being weak and launch operations against Israel and Saudi Arabia and other US allies. A war of this size would change the political and military landscape for years.

If a war started without China supporting the US. I think the US and Nato would have to surrender Seoul. Sure they could bombard the north for months on end from air craft carriers. But the North with its huge army would over run the South in days. Any defences the south has would be flattened by long range weapons.

I think the real action that Nato should take and probubly will is putting pressure on China to raise sanctions higher. Maybe cause China to blockade North Korea to a degree. If the North threatens China's relationships with the rest of the world China might allow the impossition of more sanctions. But in all honesty we have already sanctioned the hell out of North Korea and they don't seem to be stopping.

But if China imposed sanctions on the North we might see over the next decade changes gradually from North Korea. Also once Kim is dead his successor might thaw relations. Here's hoping a return to war in Korea does not occur.

I won't lie, North Korea scares the piss outta me. This is what we SHOULD be focused on, not Iraq. Note I do not mean bomb them, because that could escalate into nuclear WW3 pretty damn quick.

I... don't see the difference.

The Taliban wasn't widely supported either.  They were basically propped up by the Pakistan Taliban and Bin Laden at that point.  They had long gone out of favour with the people.

They're more popular now then they were when NATO invaded due to the whole making deals with warlords and being surprised they have a corrupt government approach.

This is double plus not good.  They've made and used nukes, may have more, and have sent a clear message that they intend to expand their potential beyond what it already is.  They have a military of more than a million people, too, so invasion (even without nuclear retaliation considered as a threat) is no small task regardless of what China may or may not desire.  This is worsened by the fact that there are no concessions that can be given to rectify this situation - any economic demands they make only make future attacks more deadly should they come to pass.  This is a serious rock and a hard place issue, and I can only hope there's a solution that isn't readily apparent.  The only good one seems to be internal discord, but considering the condition of North Korea over the last few decades that doesn't seem likely.

Maybe north Korea respond to a "provocation" of the south... this island near the border between the two countries currently held some military exercise from the south Korea...

Yes but the Koreans are one people and consider themselves as such, the South Koreans overseeing security in the North will not be seen as having foreign invaders to such a degree.

Also while the Taliban were not supported by the population as a whole there was enough support for fundamentalist Islam that the secular democratic state that was set up was simply never going to appease a large segment of the population. The idealogical reasons for opposing a new government in N.Korea are much less problematic.

Basically Afghanistan can be seen in the wrong light as a foreign occupation against the idealogy and religion of much of the population. North Korea would be a non-foreign force without any major idealogical or religious problems.

In fact the major problem is likely to be economic rather than politcal, re-unification would require bringing the North Korean economy up to near the level of South Korea. It nearly bankrupt West Germany to do that for East Germany and North Korea is in worse shape than East Germany was.

I think it sounds much too nice.

Even though they likely hate their government, i imagine the people see the south Koreans still as nothing more then brainwashed by the west.

As for the major problems being economic... I don't know how you see that as a lesser problem.

Economics trumps Religion everytime.

You don't go from, standoff for decades, followed by bloody invaision with help from foreiners that kills many of your relatives to united country.