On Killing by LtCol Dave Grossman, 2009, Excerpts
Soldiers are always under authority in combat. The relationship between the potential killer and the authority that influences the decision to kill can be generalized into a number of factors: proximity of the authority figure, respect for the authority figure, intensity of the authority figure’s demands, and the authority figure’s legitimacy.
Do not under estimate the influence of leadership in enabling killing on the battlefield. The leader’s mere presence is not always sufficient to ensure killing activity. To be truly effective, soldiers must bond to their leader just as they must bond to their group. The leader must communicate a clear expectancy of killing behavior. When he does, the influence can be enormous. But the price for the leader who has lived through such a situation is high. He must answer to the widows and the orphans of the men, and he must live forevermore with what he has done to those who entrusted their lives to his care.
The drill sergeant teaches that physical aggression is the essence of manhood and that violence is an effective and desirable solution for the problem that the soldier will face on the battlefield. The drill sergeant also teaches obedience. Throughout training the drill sergeant will not tolerate a single blow or a single shot executed without orders and to point an empty weapon in the wrong direction or to raise a fist at the wrong time merits the harshest punishment.