Nazi Germany invades Poland, marking the start of World War II. This invasion leads Britain and France to declare war on Germany.
The Japanese Navy attacks the United States naval base at Pearl Harbor, Hawaii, leading the United States to enter World War II.
Adolf Hitler and the Nazi Party take control of Germany, initiating aggressive expansionist policies.
Japan invades Manchuria, setting a precedent for further aggression in Asia.
Italy's invasion of Ethiopia exposes the weakness of the League of Nations and encourages other aggressive powers.
Nazi Germany and the Soviet Union sign a non-aggression pact that includes secret agreements to divide Eastern Europe.
Germany violates the Treaty of Versailles by remilitarising the Rhineland, challenging the post-World War I peace settlement.
The appeasement policy of Britain and France allows Germany to annex the Sudetenland, emboldening Hitler's expansionist agenda.
Germany annexes Austria without significant opposition, furthering its territorial ambitions.
Japan invades China, leading to a prolonged conflict that further destabilises the region.
Germany occupies Czechoslovakia, demonstrating the failure of appeasement and escalating tensions in Europe.
Mussolini's Italy invades and occupies Albania, expanding its influence in the Balkans.
Nazi Germany launches Operation Barbarossa, a massive invasion of the Soviet Union, significantly escalating the war.