Kindhearted people might, of course, think there is some ingenious way to disarm or defeat an enemy without too much bloodshed and might imagine this is the true goal of war. Pleasant as it sounds, it is a fallacy that must be exposed. War is such a dangerous business that the mistakes that come from kindness are the very worst.

—Carl von Clausewitz

War is cruelty. There's no use trying to reform it; the crueler it is the sooner it will be over.

—William Tecumseh Sherman

Our line of battle extended over some eight miles and for that distance you see the dead bodies of the enemy lying in every direction, some with their heads shot off, some with their brains oozing out, some pierced through the head with musket balls, some with their noses shot away, some with their mouths smashed, some wounded in the neck, some with broken arms and legs, some shot through the breast and some cut in two with shells.

—Father James B. Sheeran

Taking another person’s life does not come naturally. Some argue that a basic human instinct must be overcome within the warrior to kill another human being. This resistance to killing decreases as the distance between killer and victim increases. Distance can be physical (standoff range), cultural (fighting across racial or cultural divides), or emotional (“servicing targets”). General S.L.A. Marshall noted reluctance of US infantrymen to fire in battle during WWII, attributing this reluctance to the natural resistance to killing. Marshall had a profound effect on US Army training in order to overcome this reluctance. In recent years, a generation of historians has debated the validity of Marshall’s research and conclusions.