Why does america still have stationed troops in south korea

Honestly this is my opinion and its not in the history books or anything. I think we still have troops in South Korea because there is so much going on Obama doesn't know what the next step should be. I am not bashing on Obama but this is simply my opinion. When you have all this cluster of anger and war and not enough people to say what to next to easiest thing to do is stay where you are and wait to see the out come of it all. In my best educated non bias opinion would be that there are other things In South Korea that needs American attention and we don't know half of what is really going on. That is my bias free opinion and my other opinion would be that Obama is not smart enough or willing enough to figure out what the next step should be to solve the problem of having all these US troops in places that don't really need to be. H

Hope this help