The Cold War
Lesson 1 of 3 9 min +50 XP

An Iron Curtain Descends

From wartime allies to rivals.

What you'll learn

  • Explain how the alliance broke down
  • Define containment
  • Describe the Marshall Plan
Allies who turned their backs

The US and USSR fought side by side to beat Hitler, then almost overnight became rivals eyeing each other across a divided Europe. An 'iron curtain' fell between them — the Cold War began not with a battle but with mistrust.

Allies become adversaries

The United States and Soviet Union fought Nazi Germany together, but their aims clashed once the war ended. The Soviets installed friendly communist governments across Eastern Europe; the West saw an expanding threat. Winston Churchill captured the mood in 1946: an iron curtain had descended across the continent, dividing a free West from a Soviet-dominated East.

Containment

American diplomat George Kennan argued the Soviet Union could not be rolled back by force but could be contained — resisted firmly wherever it tried to expand. Containment became the guiding strategy of US policy for four decades.

The Marshall Plan (1948) poured billions into rebuilding Western Europe's economies, both from goodwill and from strategy: prosperous democracies were thought less likely to turn communist. The Soviets refused to let their bloc take part, hardening the divide.

Lab · Map the two blocs
  1. Sketch a rough map of postwar Europe and draw the iron curtain from the Baltic to the Adriatic.
  2. Label two or three countries on each side (West: France, West Germany; East: Poland, East Germany).
  3. Mark where Marshall Plan aid flowed and where it was refused.
  4. Explain in a sentence how economic aid served the strategy of containment.

What you should see: You visualized the division of Europe and connected the Marshall Plan to the logic of containment.

Knowledge Check

+15 XP / correct

1. The strategy of containment aimed to…

2. The Marshall Plan is best described as…