Unification of Korea. Should the U.S. stay out of it?

[Coca-Cola]

Seems China doesn't mind south Korean to be in control of the North if the North collapses.  And China is not as close to North Korea as I thought. 

Question:  If North Korea collapses without military conflict, should the U.S. pull out of Korea all together?  I don't see China or Russia being pleased for the U.S. military to be in Korea.

http://news.yahoo.com/s/ap/as_china_nkorea_wikileaks