What is the United States interest in South Korea? How does having SK as an ally benefit America? Is it an economic interest? Geographic intrest? Please respond with facts and not partisan platitudes.
South Korea is a major economic player in the region and relations between the US and the South benefit both economically, beside that there is the legacy issue of providing defense for the South against the North, there are a variety of other issues in play as well for the US presence in South Korea. If you want facts: http://www.cfr.org/publication/11954/crisis_guide.html
South Korea was once a US protectorate and there is a signficant Korean presence here in the states. And the US has signficant economic ties to Korea and the region. If the US fails to aid South Korea, other countries that rely on the US for protection will question our allegiance to them. And American influence in the region will wane. That is why the US is very committed to protection of South Korea. US protection of South Korea is much bigger than just Korea.
I think South Korea can defend itself from North Korea without US help. South Korea is economically strong. Japan is not a threat at this time. The Russians pose no threat to South Korea at this time. I don't think China is interested in attacking South Korea at this time. I see three possibilities to explain what the USA is doing in South Korea and I suspect that each together rather than just one reason explain why the USA is in Korea. 1 The USA is there because it is there and is for irrational reasons incapable of making major changes even when doing so would be logical. 2 The USA is in South Korea to threaten China, Russia and Japan because Neocon thinking requires the USA to threaten the entire world in order to preserve order and intimidate nations that might behave badly in humanitarian terms or might be have badly in ways that threaten the interests of US campaign contributers or behave badly in terms of threatening US global military dominance. 3 The US needs well armed forces everywhere to justify paying more money to defense contractors.
The US is there for obvious historical and economic reasons, some of which have already been outlined. In addition, the US is the regional hegemon there (as it is everywhere) and it ensures the status quo and the freedom of the Seas. Leaving means letting China exert more influence on the region. And nobody wants that.
Russia supplies NK with many tech things today like most of the reactor equipment that they can make atomic weapons from. Russia plays more of a role than anyone thinks there as China doesn't sell many goods to NK because NK has no money to buy stuff with. NK only wants to bully others into giving them money instead of actually developing a business relationship with others to start trade with. Russia uses NK to start problems with SK and America and by using NK as a scapegoat it does a good job of stirring the pot. If NK would be helped in starting up productive manufacturing it could be self sufficient with the aid of the IMF and others but it never will with the leadership it has today.
