How did World War II end?
World War II ended in two stages: Germany surrendered unconditionally on May 8, 1945 (V-E Day) after Allied forces overran Berlin and Hitler committed suicide. Japan surrendered on August 15, 1945 (V-J Day), after the atomic bombings of Hiroshima and Nagasaki and the Soviet declaration of war. The formal Japanese surrender was signed aboard the USS Missouri on September 2, 1945.
The end of World War II was a staggered process, with the European and Pacific theaters reaching their conclusions months apart but through similarly overwhelming applications of military force against regimes that had fought to the point of total collapse.
In Europe, the end began with the Allied invasion of Normandy on June 6, 1944 (D-Day), which opened a major Western Front that Germany could not sustain alongside the massive Soviet offensives in the East. Through the summer and fall of 1944, Allied forces liberated France, Belgium, and the Netherlands while the Red Army drove westward through Poland and into Germany itself. Hitler's last gamble — the Ardennes Offensive (Battle of the Bulge) in December 1944 — failed to halt the Western Allies. By early 1945, Germany was being squeezed from both sides.
The final months were apocalyptic. Allied bombing had reduced most German cities to rubble. The Red Army's advance through Eastern Europe was accompanied by massive destruction and civilian suffering. Hitler, increasingly detached from reality, refused to surrender and ordered the destruction of German infrastructure. Soviet forces reached Berlin in April 1945 and fought a brutal battle for the capital. Hitler committed suicide in his bunker on April 30. Germany's unconditional surrender was signed on May 7, with May 8 declared Victory in Europe Day.
In the Pacific, the end came through a different calculus. American forces had been island-hopping toward Japan since 1942, with increasingly bloody battles — Iwo Jima (February 1945) and Okinawa (April–June 1945) demonstrated the ferocity of Japanese resistance. American firebombing had devastated Japanese cities — the March 1945 raid on Tokyo killed over 100,000 people. But Japan's military leadership still refused to surrender.
The atomic bombings changed the equation. Hiroshima was destroyed on August 6, Nagasaki on August 9. Between these two attacks, the Soviet Union declared war on Japan and invaded Manchuria, destroying the Japanese Kwantung Army in days. Faced with nuclear annihilation, Soviet invasion, and no realistic prospect of defense, Emperor Hirohito intervened personally to break the deadlocked Supreme War Council and accept surrender. His radio broadcast on August 15 — the first time most Japanese had heard the emperor's voice — announced Japan's capitulation. The formal surrender ceremony took place on September 2, 1945, aboard the USS Missouri in Tokyo Bay, ending the deadliest conflict in human history.