Strategic bombing during World War II

Strategic bombing in World War II was when countries used large groups of airplanes to drop bombs on factories, cities, and transportation systems. The goal was to stop the enemy’s ability or will to fight by damaging its infrastructure and affecting its people.

This kind of bombing started when Germany invaded Poland on 1 September 1939, and its air force attacked Polish towns. As the war grew, both Axis and Allied nations carried out such bombings. Britain responded to German attacks with its own raids on German military bases in March 1940. In September 1940, Germany bombed British cities in what became known as the Blitz.

From 1942, British bombing shifted toward industrial and civilian areas. At the same time, the United States joined with the Royal Air Force in what was called the Combined Bomber Offensive (CBO). British bombers usually flew at night, while American planes attacked during the day. In 1943 the CBO focused on destroying Germany’s fighter aircraft production, later targeting V-weapon sites and oil plants.

Daylight U.S. raids used B‑17 and B‑24 bombers with precision devices like the Norden bombsight to target factories and railways. British night attacks used large numbers of Lancasters and Halifaxes to hit entire cities. These huge bomber fleets, often over 1,000 strong, aimed to overwhelm German defences.

Major Allied raids on oil refineries, transportation hubs, factories, and cities like Hamburg (Operation Gomorrah, July 1943) caused firestorms and mass damage. Hamburg lost about 60% of its housing and tens of thousands died. Attacks on refineries and transport systems severely hurt Germany’s ability to move supplies and fuel its army. By late 1944, Allied bombers, protected by fighters like the P‑51 Mustang, damaged German military and infrastructure so deeply that Germany's war effort collapsed in early 1945.

In the Pacific, the U.S. initially used B‑29 Superfortress bombers from bases in China, but these were limited in range. After capturing islands like Saipan and Tinian in mid‑1944, B‑29s could reach deeper into Japan. From late 1944, incendiary bombing on Tokyo and other cities created massive firestorms. On March 9–10, 1945, over 330 B‑29s dropped napalm bombs on Tokyo, killing more than 100,000 people and destroying large areas. In August 1945, the U.S. dropped atomic bombs on Hiroshima and Nagasaki .

After the war, the United States conducted the Strategic Bombing Survey. It confirmed that Allied bombing significantly damaged Germany’s oil production and transport systems and helped end the war. However, German aircraft, steel, and tank production even increased during the bombing, making overall effectiveness debatable. Civilian casualties were high—hundreds of thousands to over a million—and millions lost their homes.

Historians and ethicists continue to debate whether the bombing was necessary or moral. Some argue that destroying oil supplies shortened the conflict and saved lives. Others see the bombing of entire cities as an unethical attack on civilians.

Europe’s bombers mainly used B‑17s, B‑24s, British Lancasters and Halifaxes, escorted by long-range P‑51 Mustangs from 1943 onward. In the Pacific, B‑29s flew high-altitude missions, dropping both incendiary and atomic bombs. German defences included fighters and anti-aircraft guns, while Japan’s air defences were too weak to stop the B‑29 raids.