World War I (1914–1918)
- Start Date: July 28, 1914
- End Date: November 11, 1918 (Armistice Day), though the formal end was the Treaty of Versailles on June 28, 1919.
- Main Causes:
- Assassination of Archduke Franz Ferdinand of Austria.
- Militarism, Alliances, Imperialism, and Nationalism.
- Major Allied Powers: Britain, France, Russia, Italy, and the USA.
- Major Central Powers: Germany, Austria-Hungary, Ottoman Empire, Bulgaria.
- Key Events:
- Battle of the Somme (1916) – One of the bloodiest battles.
- Russian Revolution (1917) – Led to Russia withdrawing from the war.
- US Entry (1917) – Tipped the balance in favour of the Allies.
- Armistice – Signed on November 11, 1918, ending the fighting.
- Outcome: The Treaty of Versailles imposed heavy reparations on Germany and redrew many European national borders.
World War II (1939–1945)
- Start Date: September 1, 1939, when Germany invaded Poland.
- End Date: May 8, 1945 (Victory in Europe Day, or VE Day) for Europe, and September 2, 1945 (formal surrender of Japan) for the entire war.
- Main Causes:
- Treaty of Versailles’ harsh terms on Germany.
- Expansionist policies of Nazi Germany, Fascist Italy, and Imperial Japan.
- Major Allied Powers: USA, Britain, USSR, China, France.
- Major Axis Powers: Germany, Japan, Italy.
- Key Events:
- Invasion of Poland (1939) – The war begins.
- Pearl Harbor Attack (December 7, 1941) – Brought the US into the war.
- D-Day Invasion (June 6, 1944) – The Allies landed in Normandy, France.
- Atomic Bombs on Japan (August 6 and 9, 1945) – Dropped on Hiroshima and Nagasaki, forcing Japan’s surrender.
- Outcome:
- The Allies defeated Nazi Germany and Imperial Japan.
- The United Nations was founded in 1945 to prevent future conflicts.
- The emergence of the USA and USSR as superpowers marked the beginning of the Cold War.
Impact of the Wars:
- World War I:
- Led to the collapse of empires (Ottoman, Austro-Hungarian, Russian).
- Redrew the map of Europe.
- Set the stage for World War II due to unresolved tensions.
- World War II:
- Decolonization of Africa and Asia began as European powers weakened.
- For decades, the Cold War between the USA and the USSR shaped global politics.
- The development of nuclear weapons transformed international military strategy.