World War II (detail from Pearl Harbor photo)

Storming Fortress Europe

American war planners had long wanted to make a direct assault on northwest Europe, but the British had refused. Roosevelt deferred to Churchill, and neither heeded appeals from Joseph Stalin—who was battling Nazi expansion eastward into Russia—to open a second front in the west. But in spring 1943, the British relented. The Allies agreed to launch an assault across the English Channel into France.

In the summer of 1943, the U.S. Army Air Corps expanded daylight bombing runs against industrial targets in Germany and occupied Europe. Squadrons of bombers flew hundreds of miles—far beyond the range of available fighter escorts—to attack oil fields, refineries, and factories. Dozens of planes and their crews were lost. In early 1944, finally accompanied by protective escorts, bombers struck aircraft plants and rail networks.

By the spring of 1944, a year of Allied bombing had weakened Germany’s war machine. The Allies finally were ready to strike directly at the heart of Nazi-occupied Europe.