No. 02 · The Global Conflict

World War II

From the invasion of Poland in September 1939 to the surrender of Japan in September 1945, World War II was the deadliest conflict in human history. It involved more than 30 countries and reshaped the political, social, and technological landscape of the modern world.

1939 War begins

1945 War ends

~70–85M Total deaths

30+ Nations involved

Overview

World War II was fought between the Allies — principally the United Kingdom, the Soviet Union, the United States, and China — and the Axis powers of Germany, Italy, and Japan.

The war’s roots lay in the unresolved tensions of World War I, the harsh terms of the Treaty of Versailles, the rise of fascism in Europe, and Japanese expansionism in Asia. The invasion of Poland by Germany on 1 September 1939 led Britain and France to declare war, and the conflict quickly spread across the globe.

Allied Powers

United Kingdom, Soviet Union, United States, China, France, and many others.

Axis Powers

Germany, Italy, Japan, and their satellite states.

Neutral Nations

Spain, Sweden, Switzerland, Portugal, Ireland, and others.

Timeline

1939
Germany invades Poland (1 September). Britain and France declare war. The Soviet Union invades Poland from the east.
1940
Germany invades Denmark and Norway, then France and the Low Countries. The Battle of Britain rages in the skies. Italy enters the war.
1941
Germany invades the Soviet Union (Operation Barbarossa). Japan attacks Pearl Harbor, bringing the United States into the war.
1942
The Battle of Midway halts Japanese expansion. The Battle of Stalingrad begins. Allied forces land in North Africa.
1943
Germany surrenders at Stalingrad. Italy surrenders to the Allies. The tide turns in the Pacific.
1944
D-Day: Allied landings in Normandy (6 June). Paris is liberated. The Red Army pushes into Eastern Europe.
1945
Germany surrenders (8 May). Atomic bombs are dropped on Hiroshima and Nagasaki. Japan surrenders (2 September).

Theaters

European Theater

From the Blitzkrieg across Poland and France to the brutal Eastern Front and the final assault on Germany.

Pacific Theater

Island-hopping campaigns, naval battles, and the atomic bombings that ended the war against Japan.

North African Campaign

Desert warfare between the Axis and Allies, culminating in the victory at El Alamein.

Eastern Front

The largest and deadliest theater, where the Soviet Union and Germany fought massive battles like Stalingrad and Kursk.

Technology & Innovation

World War II drove rapid advances in technology, from radar and jet aircraft to rockets and the atomic bomb. Codebreaking and computing also played crucial roles.

Radar: Helped the RAF win the Battle of Britain and improved naval detection.
Jet aircraft: Germany’s Me 262 and Britain’s Gloster Meteor pioneered jet flight.
Rockets: The V-2 was the first ballistic missile and a precursor to space launch vehicles.
Atomic bomb: The Manhattan Project developed nuclear weapons, used on Hiroshima and Nagasaki.
Codebreaking: Enigma and Lorenz decrypts at Bletchley Park shortened the war.
Aircraft carriers: Replaced battleships as the dominant naval platform in the Pacific.

Legacy

World War II ended with the surrender of Germany in May 1945 and Japan in September 1945. The war led to the creation of the United Nations, the beginning of the Cold War, and the decolonisation of many European empires.

The Holocaust, the systematic genocide of six million Jews and millions of others by Nazi Germany, left an indelible mark on human history. The war also accelerated civil rights movements, scientific research, and the formation of the modern international order.

“Never was so much owed by so many to so few.” — Winston Churchill, 1940