In Europe, both sides welcomed the attack on Pearl Harbor. Hitler, pleased that the industrial bulwark of the Allies was now preoccupied with an Asian enemy, almost immediately declared war on the U.S. Churchill and Stalin were relieved that America was finally a combatant.
By the beginning of December 1941, German troops were in Istra, a suburb only 15 miles west of Moscow. Ever since Hitler launched Operation Barbarossa at 4 a.m. on June 22, 1941, his forces had swept through Stalin's European empire. They took the half of Poland that had been partitioned to the Soviet Union in 1939, stripped...