In his excellent military history of the American Revolution, Almost a Miracle: The American Victory in the War of Independence (2007), author John Ferling writes,
Ferling makes these observations in the context of a bitter guerilla war waged by American rebels against British occupation forces in South Carolina during the American Revolution. They could have been written of every war humanity has ever fought—including the War on Terror.
"There are always those who wish to sanitize war by portraying its grand and noble deeds—which sometimes occur—while drawing a veil over its shameless side. By its nature, war is harsh, brutal, and pitiless, and while it can call out the best in humankind, it can also awaken the darkest side of human nature, arousing in many participants a cold hearted callousness. For most, danger begets fear. For some, fear sires ferocity and ferocity spawns a ruthlessness that subsumes compassion. For still other men, more than is gratifying to acknowledge, soldiering is a license to unleash iniquitous qualities that they had struggled to suppress in peacetime." (p. 453)