Chiang [Kai-shek]'s political choices made a huge difference in the lives of many people in China, sometimes disastrously so. … His greatest crime was ordering the destruction of dykes on the Yellow River in 1937 in an effort to slow Japanese advances. The explosions shifted the course of the river and flooded parts of three provinces. At least 800,000 Chinese villagers drowned in the floods, a figure that is more than double the highest estimated number of Chinese casualties during the Rape of Nanjing several months earlier.