In early 1941, Hitler’s armies ruled most of Europe. Churchill’s Britain was an isolated holdout against the Nazi tide, but German bombers were attacking its cities and German U-boats were attacking its ships. Stalin was observing the terms of the Nazi-Soviet Pact, and Roosevelt was vowing to keep the United States out of the war. Hitler was confident that his aim of total victory was within reach.
By the end of 1941, all that changed. Hitler had repeatedly gambled on escalation and lost: by invading the Soviet Union and committing a series of disastrous military blunders; by making mass murder and terror his weapons of choice, and by rushing to declare war on the United States after Japan’s attack on Pearl Harbor. Britain emerged with two powerful new allies—Russia and the United States. By then, Germany was doomed to defeat.