75 years ago, on Dec. 13, 1937, Japanese troops captured the city of Nanjing, then the capital of the Chinese republic led by Chiang Kai-shek and went on a six-week campaign of carnage and slaughter that would be forever remembered as the “Rape of Nanjing.” Reports document widespread rape and the indiscriminate killing of civilians; some death tolls estimate over a quarter of a million people were killed. The incident, though, still rankles Sino-Japanese relations. Japanese nationalists contend that the death tolls are inflated and the majority killed were resisting Japanese occupation. To this day, pages in Japanese school history textbooks can incite heated protests on the streets in China. Then and now, the Nanjing massacre remains one of the darkest events of the last century.—Ishaan Tharoor