Troll is completely correct: soldiers are NOT unthinking automatons and other soldiers don't care for any kill-crazy fools. In 'Nam and in other wars both sorts were liable to be fragged before they got others killed. (And the incident with the sergeant in the 101 Airborne was NOT fragging -- it was simply murder. Fragging was usually done to eliminate an incompetent commander, a kill-crazy fool, a the-book-says-do-it-this-way martinet, or similar sorts. The media, once again, have gotten it wrong.)

As a former Infantry platoon leader (forced into it, no officer) I can assure you that an automaton will not only end up dead, s/he will kill a bunch of others along the way. One of the few times I ever gripped a .45 pistol and was glad to have it was when I was working a night shift with a crazy who actually LIKED killing and death (he as later taken away for psychiatric are and we all breathed a sigh of relief, for him as well as for ourselves).

Battle changes too rapidly for a rigid thinker -- the WWI commanders are excellent examples of this (as is Vietnam). Battle is and actually always has been "think or die" -- history is written by the generals, battles are won by the grunt on the ground.