Exploring Puritanical cultural habits in the 21st century American military, the following study focuses on U.S. Army courts-martial in the Global War on Terrorism. The study uses Emile Durkheim's original sociological interpretation of crime and deviance. That interpretation is linked with responsibility as described by Durkheim's follower Paul Fauconnet in Responsibility: A Study in Sociology ([1928] 1978) and with a new cultural reading of Max Weber's The Protestant Ethic and the Spirit of Capitalism ([1905] 1976). The study is an inductive, descriptive examination of the Puritanical aspects of American military culture based on its treatment of acts labeled as deviant and criminal in the Global War on Terrorism. Four sets of war crimes are included in the study: Abu Ghraib (which occurred in Iraq in 2004), Operation Iron Triangle (which occurred in Iraq in 2006), the Baghdad canal killings (which occurred in Iraq in 2007), and the Maywand District killings (which occurred in Afghanistan in 2010). My data include primary data collected through participation and observation as a consultant for courts-martial related to all the cases except Abu Ghraib. Records of trial, investigation reports, charge sheets, sworn statements, and other documentation are also included in the study as secondary data sources. The study illuminates how unconscious, Puritan cultural habits color and shape both military actions and their perceptions. I explore Puritanism and its influence on military law, responsibility, revenge, "magic" (in its sociological sense), and narcissism. The study concludes with observations and recommendations for changes in U.S. military law.