In 1916, Henry Morgenthau Sr., American ambassador to the Ottoman Empire, resigned. His superiors' demand that he maintain cordial relations with Turkish Islamist zealots and ethnic nationalists as they massacred the Armenian Christian minority disgusted him. "I found intolerable my further daily association with men who ... were still reeking with the blood of nearly a million human beings."
The perpetrators got away with it, as they almost invariably do. When Turkey found itself on the losing side of World War I, the victorious allied armies held a few war-crimes trials. But more pressing matters soon...