## TL;DR

World War II (1939-1945) was the deadliest conflict in human history, involving over 100 million people from 30+ countries. Axis (Germany, Italy, Japan) vs. Allies (US, UK, USSR, China, France). 70-85 million deaths. Ended with atomic bombings of Hiroshima/Nagasaki and the beginning of the Cold War.

## Core Explanation

Key events: 1939 Germany invades Poland, 1941 Pearl Harbor + Operation Barbarossa (Germany invades USSR), 1942 Battle of Midway + Stalingrad (turning points), 1944 D-Day (Normandy), 1945 VE Day + atomic bombs + VJ Day. Holocaust: systematic genocide of 6 million Jews. United Nations founded 1945. European powers declined; US and USSR emerged as superpowers.

## Further Reading

- [The Second World War (Antony Beevor)](https://www.antonybeevor.com/books/the-second-world-war/)