On Killing by LtCol Dave Grossman, 2009, Excerpts
In World War II, 80 to 85 percent of riflemen did not fire their weapons at an exposed enemy. A firing rate of 15 to 20 percent among soldiers is like having a literacy rate of 15 to 20 percent among proofreaders. Once those in the authority realized the existence and magnitude of the problem, it was only a matter of time until they solved it.
Since WWII, a new era has quietly dawned in psychological warfare conducted not upon the enemy, but upon one’s own troops. Propaganda and various other crude forms of psychological enabling have always been present in warfare, but in second half of the twentieth century, psychology began to have an impact as great as that of technology on the modern battlefield.
As a result of new training techniques, 55 percent of infantrymen were firing their weapons in the Korean War. These training techniques were further perfected, and in Vietnam the firing rate appears to have been around 90 to 95 percent. The triad used to achieve this remarkable increase in killing is desensitization, conditioning, and denial defense mechanisms. This superiority and killing ability in Vietnam, Panama, Argentina, Rhodesia Afghanistan, and Iraq amounts to total superiority in close combat.