How well they work is in question, but they do work:

http://news.bbc.co.uk/2/hi/asia-pacific/6056370.stm

It's hard to find something remotely communist in China. Sure, it's a country with one party based on the ideology of the three people's principles of the Guomindang and Maoïsm, but in reality China can no longer be called truly communist. And yes, I've  been to China already, also on the not so nice looking places.

Tibet is thrown under the bus a long time ago. Taiwan as well. That's why it isn't a country on the world maps and that's why you call it Taiwan instead of the Republic of China. That's why it isn't a member of the UN.

 I wouldn't say it's not serious. But people here aren't quite expecting a new war. The two nations have had relations freeze and thaw before.

I think most people on this board associated statements by South Korean in regards to seeking justice or retaliation as being of a purely military nature. People tend to forget that these two may be at war with eachother, but out of necessity deal with eachother in a lot of ways. It's those ways that are changing (as has already started) that The government was reffering to.

Just last year South Koreans regularily went to a Mountain Resort in North Korea (until one got shot by NK soldiers), up until this crisis SKoreans worked in and owned factories in the North Korean joint industrial site. Korea was regularily giving them large quantities of food and even some financial aid.

There are many ways to strike hard at NK without using the military and that's what the south is doing. The ceasation of aid, seeking tougher sanctions, reconstructing the DMZ soldier based propaganda towers (that had been up before), and I'm sure we'll see an upswing in activist groups doing propaganda balloon drops. It's the North that's put in the tough position, because military outbursts is the only tool they have. And at this point it's one that inherently brings about... well... destruction. They can't even really count on China for anything either. China actually doesn't gain much anymore by having North Korea there, aside from illegal migration and smuggling concerns. But they do get great business oportunities with the South. I can't help but thing there's a bit of a conflict between traditional schools of thought on NK and the new school thought on doing business.

What we need to figure out is why that sub fired a torpedo. Was it a rogue ship captain? Direct military orders? A presidential dictat? If it's the latter, Jong Il must have some reason for seeking the tension. Some have theorized it's to help get his people to rally behind his third son when he takes over the country.

If it was the military, it may infact signal that the Country is starting to see a rift in it's administration. And I wouldn't be surprised if Jong Ill's reign was ended by the military. Whether the country would be better or worse underneath the North Korean Military (which it kind of is now anyways, since Jong Ill is their leader), is a hard one to call.

If it was simply a mistake or rogue captain. Well then 3 guesses as to who just got executed. It would probably be under this scenario that things go back to the status quo quickest.

N. Korea scraps S. Korea naval accord

Last Updated: Thursday, May 27, 2010 | 5:18 AM ET Comments20Recommend14

The Associated Press

North Korea said Thursday that it will scrap an accord aimed at preventing accidental naval clashes with South Korea after Seoul blamed Pyongyang for a torpedo attack that sank a South Korean warship.

Thousands of South Koreans, including veterans, take part in an anti-North Korea rally at the Seoul City Hall Plaza on Thursday. (Jo Yong-Hak/Reuters)

Tension on the divided peninsula has risen dramatically since a team of international investigators said last week that a torpedo fired by a North Korean submarine tore apart and sank a South Korean warship on March 26, killing 46 sailors.

North Korea has denied its involvement in the sinking and warned any retaliation would mean war.

On Thursday, North Korea's military said it will "completely nullify" an inter-Korean accord aimed at preventing accidental armed skirmishes along the disputed western sea border — a scene of three bloody maritime battles between the two Koreas.

"Immediate physical strikes will be launched," against any South Korean ships that intrude into North Korean waters, the country's military said in a statement, carried by the official Korean Central News Agency.

It said it will also start a review to possibly ban South Korean personnel and vehicles from entering a joint industrial park in the North Korean border town of Kaesong — the last remaining major inter-Korean reconciliation project. It gave no timeframe, however.

The military said the measures are its first-phase reaction to "the reckless moves of the group of traitors and confrontation maniacs," suggesting that more could follow.

A South Korean Defence Ministry official said South Korea will "resolutely" deal with the North's measures, though did not elaborate. He spoke on condition of anonymity, citing department policy.

The announcement came hours after a fleet of South Korean warships staged a large-scale anti-submarine drill off the west coast despite North Korea's warnings that such exercises will drive the peninsula to the brink of war.

The two Koreas are still technically at war because their 1950-53 conflict ended with an armistice, not a peace treaty. The U.S. stations 28,500 troops in South Korea, a legacy of the Korean War.

South Korean troops on alert

South Korean and U.S. troops are on their highest alert since North Korea's second nuclear test in May last year, reports said.

In this May 19, 2010 photo, navy members stand guard near the wreckage of the naval vessel Cheonan, which was sunk on March 26 near the maritime border with North Korea. (Lee Jae-Won/Reuters)

The mass-circulation JoongAng Ilbo newspaper, citing an unidentified Seoul official, reported Thursday the South Korean-U.S. combined forces command raised their surveillance level called Watch Condition, up a level from 3 to 2. Level 1 is the highest.

South Korea, backed by the U.S., Japan and other allies, has begun carrying out punitive measures that range from slashing trade and resuming propaganda warfare to barring the North's cargo ships — the strongest it can implement short of military action.

North Korea quickly responded by threatening to cut ties with South Korea, wage "all-out counterattacks" against psychological warfare operations and bar South Korean ships and airliners from its waters and airspace.

"We will never tolerate the slightest provocations of our enemies, and will answer to that with all-out war," North Korean Maj. Gen. Pak Chan Su, a Korean War veteran, told broadcaster APTN in Pyongyang. "This is the firm standpoint of our People's Army."

South Korea pressed ahead Thursday with anti-submarine drills to boost readiness against any North Korean provocations.

During a one-day exercise off the west coast, 10 warships fired artillery and other naval guns and dropped anti-submarine bombs off Taean, about 150 kilometres south of Seoul, the navy said.

South Korea is also planning two major joint military drills with the U.S. off the west coast by July in a display of force intended to deter future aggression by North Korea.

North Korean state media, citing the drills, criticized South Korea on Wednesday for "driving the situation to the brink of explosion."

Read more: http://www.cbc.ca/world/story/2010/05/27/north-korea-china.html#ixzz0p8CnnmDa

If the situation does escalate to armed conflict, naval battles would be the most likely occurrence. Even having this accord in place didn't prevent the Cheosan from being attacked.

For the record I hope this crisis does not escalate and is quickly and peacefully resolved. However the situation is very complex and we must look at the entire history of the divided Korea and not just the last few months in order to analyze it properly.

Many here think, and I can understand why they do that it would be best if the leadership of North Korea could be overthrown and Korea reunified. However many in the west thought the same thing in the 1950's and in the end a war occurred which caused millions of casualties but ended in a stalemate without a peace treaty between the north and south leaving them in a state of war which persists until the present day. The only thing in place which is preventing hostilities is a cease fire agreement.

A couple of people in this thread have indicated that China would stay out of it and that they have no reason to help the North. It is my belief that if the South with the support of the west starts a war China will intervene, if only to preserve a buffer between itself and the US military. Keep in mind that South Korea still hosts US troops and that the number of those troops can always be increased. In any case I can see China being vehemently opposed to US forces being stationed in the North in case of reunification.

I believe that the best course of action is to have a peaceful resolution. However if the west along with South Korea decide to remove the North's leadership they will have to sit down with China and work out an arrangement whereby the North would be demilitarized. If unilateral action is taken I believe there will be dire consequences not only for the region but for the rest of the world both in the economic and security respects.

But the U.S. troops in South Korea are there as a direct result of North Korea. Were the threat of North Korea to evaporate with unification, the role of the U.S. Military in the region would be re-examined by both the U.S. and Korea. 

Also, the notion that China would ally themselves with North Korea in a military conflict for the purpose of avoiding the United States is a bit counterproductive, considering that it would put them into direct confrontation with the U.S. army, as well as South Korea's, Japans, and numerous other U.N. nations.

There's also the fact that total trade between China and North Korea is worth about 2.7 billion, while trade between China South Korea is worth about 156.2 Billion.

It's been suggested before that one of the key reasons China supports North Korea is because it fears that the country's collapse would swell the already large numbers of refugees crossing the border in to China. It may be a good reason for support, but it would hardly at all be a reason to be drawn in to world war 3.

There is no way China would want to involve itself militarily in such a dispute.

Wouldn't North Korea's collapse only decrease the number of fleeing refugees in the long run?  Yeah, the initial devastation would cause quite a few people to try and get out, but once the ROK fully takes over, I doubt too many people would want to flee to China.

I agree that China has an important economic relationship with the South Koreans and an even bigger one with America however I believe that when it comes to China that issues of security trump economics.

If we look at the situation in 1950, China was in economic ruin and had hardly any military industry to speak of. They had just come out of the devastation of world war 2 as well as a civil war. They were in an infinitely worse position than they are in now and yet they chose to intervene against a far better eqipped West.

And while they may take an economic hit by getting involved, the economic fallout would swing in both directions. If you want to look at a more recent event to demonstrate China's policy of no compromise on security, it would be the Tibet riots. They occurred just prior to the olympic games when all eyes were on China. China's response was to quell the riots without giving in to any demands.

All I'm saying is, is that when it comes to matters of security it would be far wiser for South Korea and America to negotiate rather than repeating history albeit against a far more formidable opponent in today's well equipped and loaded with cash reserves China.

edit- Hopefully it doesn't come to such a situation but I sincerely hope that the people in power in Washington and Seoul negotiate rather than act unilateraly. I'm also hopeful that China will get more involved behind the scenes to rein in the North Koreans.

FYI:

China has just stated they will not protect North Korea from the consequences of them sinking the Cheonan.

Queue the sad little violin.