Americans, including GIs, were losing their once reflexive faith that the U.S. military, with all its skill and firepower, would prevail in Vietnam as it had so often throughout history. Also shattered was the faith that America's fighting forces were inherently more virtuous than their enemies. The unraveling of that conviction began in earnest in 1969 with the revelation that American soldiers had murdered hundreds of unarmed and unresisting women, children, babies, and old men in the village of My Lai.

For many people, the shocking news came first in the form of several horrifying photographs. One shows almost two dozen dead Vietnamese bodies on a dirt road. Many have fallen in a twisted pile; some are partially naked. Another photograph shows a woman lying in a field with her legs drawn up under her body. Her conical straw hat has flipped off her head. If you look closely you can notice that a large portion of her brain lies exposed beneath the hat.