Of course there's always denial.
Balancing the obligation to kill with the resulting toll of guilt forms a significant cause of psychiatric casualties on the battlefield. Philosopher-psychologist Peter Marin speaks of the soldier's lesson in responsibility and guilt. What the soldier knows as a result of war is that "the dead remain dead, the maimed are forever maimed, and there is no way to deny one's responsibility or culpability, for those mistakes are written, forever and as if in fire, in others' flesh."
Ultimately there may be no way to deny one's responsibility or culpability for mistakes written "forever and as if in fire, in others' flesh," but combat is a great furnace fed by the small flickering flames of attempts at denial. The burden of killing is so great that most men try not to admit that they have killed. They deny it to others, and they try to deny it to themselves. Dinter quotes a hardened veteran who, upon being asked about killing, stated emphatically that
"Most of the killing you do in modern war is impersonal. A thing few people realize is that you hardly ever see a German. Very few men — even in the infantry — actually have the experience of aiming a weapon at a German and seeing the man fall."
Even the language of men at war is full of denial of the enormity of what they have done. Most soldiers do not "kill," instead the enemy was knocked over, wasted, greased, taken out, and mopped up. The enemy is hosed, zapped, probed, and fired on. The enemy's humanity is denied, and he becomes a strange beast called a Kraut, Jap, Reb , Yank, dink, slant, or slope. Even the weapons of war receive benign names — Puff the Magic Dragon, Walleye, TOW , Fat Boy, and Thin Man — and the killing weapon of the individual soldier becomes a piece or a hog, and a bullet becomes a round.

For next time I'll try to gather some quotes by soldiers who didn't give a shit just for the sake completness. I remember this book has some of that too.