Spreading out your forces to several different places isn't wise... Remember the roman empire? The mongols? the huns? Germany in WWII? Napoleon? Etc... Many of these people tried to fight too many fronts or went too far when waiting for a bit would be better.
The united states isn't planning on doing this, though. Instead of having bases in Europe AND the middle east, the neo conservatives want to liquidate the european bases and re station those troops in the middle east. Permanantly.