On Killing: The Psychological Cost of Learning to Kill in War and Society

After explaining the psychological tolls that extended combat and killing have on soldiers, Grossman focuses on how the military leadership and American society failed Vietnam veterans.

Subjected to highly effective psychological conditioning, combat soldiers in Vietnam had a 90-95% ratio of fire. The military trained them to kill but did not help them cope with the aftermath. Conditions in the Vietnam war made the killings particularly traumatic. Since it was a guerrilla war, the line between combatants and non-combatants was blurred, with soldiers sometimes shooting women and children. There were no safe zones to which soldiers could go for needed respite. Unlike past wars, soldiers were deployed individually for one-year tours in Vietnam. As a result, they lacked the psychological support that comes from close-knit combat units. Even when sent home, they traveled individually and did not have a period to exchange stories with comrades and prepare for re-engagement with civilian life.

When Vietnam veterans returned from battle, they were often met with hostility. People spat upon some of them and called them murderers. Grossman explains that the lack of societal support greatly contributed to the high rate of PTSD in soldiers returning from Vietnam. In contrast, soldiers returning from World War II were celebrated and told they had done right by their country. Such social support helps to mitigate the intensity of psychological trauma. Even those Vietnam veterans who experienced mild trauma on the battlefield had a high likelihood of PTSD because of the hostile response to them at home. The silent and long-term suffering of Vietnam veterans seems to be a motivating factor in Grossman’s desire to expose the difficulty of what soldiers are asked to do.

S.L.A. Marshall was a US Army “historian in the Pacific theater during World War II and later became the official U.S. historian of the European theater of operations” (3). Heading a large team of historians, he supervised a project in which thousands of soldiers in the Pacific and European theaters were interviewed. He found that only 15-20% of combat riflemen in World War II fired at the enemy. His findings got considerable attention, and the military changed its training methods to increase this ratio of fire.

However, historians raised questions about the accuracy of Marshall’s findings later in the 20th century. Grossman uses this research to support his premise that there is a natural inhibition against killing a member of one’s own species. When that inhibition is overcome via psychological training and conditioning, there is a need to consider the psychological effects on the combat soldier.