First off we have reduced our force in ROK, so the premise is faulty. Pat might recall it was Ronald Reagan who halted the first draw-down that Carter ordered. A new draw-down was ordered by Bush, but only partly implemented. That's because it is being used as a bargaining chip to stop the nuclear weapons program in PRK. Currently the combat force consists of 4 fighter wings (3 F-16 squadrons and one A-10 squadron) , 1st Armored brigade, 2d combat aviation brigade, and 210th fires brigade.
I'm not sure pulling out of NE Asia, and allowing an even bigger arms race than we are currently seeing, is such a great idea. As it is ROKN and JSDF are building some sophisticated warships to counter the PLAN.