In the Korean War, the Russians had pilots in many of the MiG-15s getting live fire training against our fighter pilots.  Notice that the Russians are getting similar training in Syria for ground support missions and in the Ukraine training their ground forces and anti-aircraft units.  China is not the only country that has ambitions in East Asia.  

The US, South Korea and Japan should seriously consider setting up a buffer zone between these two super powers who want to control that region.  May be occupying North Korea, Manchuria, Siberia and Mongolia may be a good size chunk of real estate to keep China and Russia our of everyone's hair for a few centuries.