The first half of the twentieth century brought almost unimaginable violence and destruction. Shaken by the rapid cultural change and economic collapse that followed the tragedy of World War I, many Europeans embraced the radical politics of communism and fascism. Totalitarian dictators like Stalin and Hitler capitalized on the desire for social order, building dictatorial regimes that demanded total allegiance to an ideological vision. Even as these regimes rewarded supporters and promised ordinary people a new age, they violently repressed their enemies, real and imagined. The vision proved fatal: the great clash of ideologies that emerged in the 1920s and 1930s led to history’s most deadly war.

Only the reluctant Grand Alliance of the liberal United States and Great Britain with the Communist Soviet Union was able to defeat the Axis powers. This alliance, however, did not long survive the end of the war. Trust quickly broke down. Europe would be divided into two hostile camps, and Cold War tensions between East and West would dominate European and world politics for the next fifty years.