Repercussions

Where the League of Nations failed, the UN was built with American participation and great-power veto rights on the Security Council. Founded in 1945 with 51 members, it now has 193 — the closest thing to a world government humanity has created.

The alliance of convenience between the US and USSR dissolved into 45 years of ideological conflict, nuclear standoff, and proxy wars. The Iron Curtain divided Europe; Germany was split in two; the nuclear arms race threatened human extinction. The Cold War defined global politics until 1991.

Six million Jews and millions of others systematically murdered. The Holocaust shocked the world into creating the concept of genocide, the Nuremberg war crimes trials, the Universal Declaration of Human Rights, and the State of Israel. 'Never again' became a phrase — though not always a policy.

The atomic bombings of Hiroshima and Nagasaki opened an era in which human civilization could end itself. The US-Soviet nuclear arms race peaked at 70,000 warheads. Nuclear deterrence has prevented great-power war since 1945 — but the threat has never gone away.

WWII fatally weakened the European colonial empires. Britain, France, and the Netherlands had been occupied or exhausted; they could no longer enforce empire. Between 1945 and 1975, over 80 nations gained independence. The map of Asia and Africa was redrawn entirely.

The US provided $13 billion ($150 billion today) to rebuild Western European economies, explicitly to prevent communist parties from capitalizing on postwar misery. It was the most successful foreign aid program in history — and ensured Western Europe's alignment with the United States.

The North Atlantic Treaty Organization, founded 1949, created a permanent US military commitment to European defense. 'An attack on one is an attack on all.' NATO made a Soviet invasion of Western Europe suicidal — and arguably kept the Cold War from turning hot in Europe.

The Holocaust made international support for a Jewish homeland irresistible. Israel declared independence in May 1948. The Arab-Israeli wars that immediately followed, and the displacement of 700,000 Palestinians (the Nakba), created conflicts that still define the Middle East.

The US entered WWII as a great power and emerged as a superpower. Its economy was the only major one not devastated by the war — producing 40% of global GDP. The dollar became the world reserve currency. American cultural influence — films, music, consumer goods — spread globally.

The determination that Europe must never again destroy itself led to the European Coal and Steel Community (1951), then the EEC, then the European Union. France and Germany — enemies for three wars in 70 years — became partners. It is the most successful peace project in history.