Although it would certain be cheaper (in the short term) if SEA (South East Asia) were to handle these things in country, that is not in the best interest of the United States. The best way to develope economic relations with other nations is to cultivate military interdependence with other nations.

You do know that the real reason that China is upset with NK is because they are afraid we would try to initiate a regime change in NK that might end up with American Military power along that border. That would force them to deal more closely with us, which is something they dont believe they have to do.