Given that the US military is undergoing its "transformation" during combat, as opposed to training, the "tooth to tail" ratio is being changed as well..and the tail is getting bigger, and longer..thus, the emphasis of total troop strength as a number per se, in and of itself, is misleading..I recall that something like 50% of USA KIA in the war, combat deaths, were behind the front, in supply convoys....
USA is downsizing the military to the point, where it can not even defend itself.