World History — 20th Century Conflicts

More people died in 20th-century conflicts than in any other century in human history — an estimated 160 MILLION. From trench warfare to atomic bombs, from genocide to nuclear standoff, these wars transformed every continent. Understanding them is understanding the world we live in now.

Triggered by the assassination of Archduke Franz Ferdinand (June 1914), alliances dragged most of Europe into war.\n\n- **Central Powers**: Germany, Austria-Hungary, Ottoman Empire\n- **Allies**: Britain, France, Russia (then US after 1917)\n- **Trench warfare** — new weapons (machine guns, poison gas, tanks) meant massive casualties with no territorial gain\n- **~17 million deaths**\n- **Treaty of Versailles (1919)** — blamed Germany, imposed harsh reparations\n\nThe war reshaped Europe, ended four empires, and sowed the seeds of WWII.

Amid WWI, Russians overthrew the Tsar and then the provisional government.\n\n- **Vladimir Lenin** and the Bolsheviks seized power\n- **Civil War** (1917-23) between "Reds" (communists) and "Whites" (anti-communists)\n- USSR (Soviet Union) formed in 1922\n- **Joseph Stalin** took power after Lenin's death (1924); industrialized the USSR through brutal collectivization; killed millions\n\nThe USSR would dominate half of Europe and lead a global competition with the US for 70 years.

Hitler's rise — driven partly by WWI's unjust peace — led to the bloodiest conflict in human history.\n\n- **Nazi Germany** invaded Poland (Sept 1939), then much of Europe\n- **Japan** attacked Pearl Harbor (Dec 7, 1941), bringing US into war\n- **Holocaust** — Nazi Germany systematically murdered 6 MILLION Jews + millions of others\n- **D-Day (June 6, 1944)** — Allied invasion of France\n- **Atomic bombs** on Hiroshima and Nagasaki (Aug 1945) — Japan surrendered\n\n**70-85 MILLION deaths**. Europe and East Asia devastated.

After WWII, the US and USSR emerged as superpowers — and rivals.\n\n- **Not a "hot" war** — but proxy conflicts everywhere\n- **Nuclear arms race** — both sides built thousands of nukes\n- **Berlin Wall (1961-89)** — symbol of divided Europe\n- **Cuban Missile Crisis (1962)** — closest the world came to nuclear war\n- **Vietnam War (1955-75)** — US intervention to stop communism, failed\n- **Korean War (1950-53)** — divided Korea, still divided today\n\nThe Cold War ended in 1991 when the Soviet Union collapsed. But its legacy — NATO, nuclear weapons, divided Korea — persists.

In the decades after WWII, European empires dissolved:\n\n- **India and Pakistan** (1947) — independence from Britain\n- **African nations** — most gained independence 1950s-60s\n- **Vietnam** — from France, then war with US\n- **Algeria** — 8-year war with France (1954-62)\n\nFrom 1945 to 1990, the number of countries in the world nearly TRIPLED. Borders drawn by colonizers often don't match ethnic realities — causing many ongoing conflicts.

- **Middle East** — Israeli-Palestinian conflict (1948-present), Iran Revolution (1979), Iraq wars\n- **Yugoslavia breakup (1990s)** — brutal ethnic wars, Bosnian genocide\n- **Rwandan genocide (1994)** — 800,000 killed in 100 days\n- **Chinese Tiananmen Square (1989)** — pro-democracy protests crushed\n- **South African apartheid ends (1994)** — Nelson Mandela elected\n- **9/11 attacks (2001)** — reshape 21st century\n\nEach conflict has a story; each continues to influence today's politics.

Patterns emerge:\n\n1. **Nationalism** + ethnic/religious tensions = explosive\n2. **Alliances** can pull small conflicts into world wars\n3. **Economic crises** (Great Depression, German hyperinflation) fuel extremism\n4. **Weapons advances** make wars more destructive\n5. **Decolonization** is messy — but rarely undone\n6. **Cooperation** (UN, EU, NATO) reduced direct great-power war after 1945\n\nUnderstanding WHY wars started helps us prevent the next one.