This essay explores the more than 230-year-long development of the military justice system of the United States, a process that began even before the country's constitution was written. It examines the contributions to the jurisprudence of other countries made by the justice system of the U.S. armed forces and looks at some of the most important controversies accompanying its development. It also presents some of the contemporary issues facing both the U.S. military and civil society in the early 21st century, as the United States conducts actions against hostile non-state actors who threaten both the security and human rights of democracies around the world.