Lesson 1: The Cold War Begins

Lesson Focus

After World War II, the United States and the Soviet Union emerged as rival superpowers. This lesson explores how their conflicting ideologies sparked decades of global competition, military buildups, and political division, starting in Europe.

People to Know

Harry S. Truman, Nikita Khrushchev

Learning Objectives

• Explain why the U.S. and the Soviet Union, former allies, became political rivals with competing ideologies after World War II.
• Describe the results of rising superpower tensions, including military alliances, the arms race, and the division of Germany.

After WWII, opposing ideologies created intense rivalry. Fearing the West, the Soviet Union refused to liberate Eastern European nations.

Instead, the Soviet army remained and established pro-Soviet regimes in countries like Poland and Romania, turning them into satellite states.

This aggressive expansion created an "Iron Curtain" that divided Europe and set the stage for a global power struggle with the United States, sparking the Cold War.

To counter Soviet expansion, President Truman announced the Truman Doctrine in 1947, providing aid to countries like Greece threatened by communism.

This was followed by the Marshall Plan, which offered billions to rebuild war-torn Europe and reduce communism's appeal. These actions established the U.S. policy of containment.

The Soviets rejected this aid and formed their own economic alliance, COMECON, deepening the divide between East and West.

When the Western powers moved to unify their German zones, the Soviets responded in 1948 by blockading West Berlin to force them out. Rather than using military force, the U.S. and Britain launched the Berlin Airlift.

For over 10 months, they flew in millions of tons of supplies. This heroic effort forced the Soviets to lift the blockade in 1949 and led to the creation of a separate West and East Germany.

The search for security led both sides to form powerful military alliances.

In 1949, the United States, Canada, and Western European nations created the North Atlantic Treaty Organization (NATO), promising mutual defense.

In response, the Soviet Union and its Eastern European allies formed the Warsaw Pact in 1955. This development, fueled by events like the Korean War, divided Europe into two heavily armed, opposing camps, increasing global tensions.

The Cold War rivalry fueled a terrifying arms race as both superpowers sought military superiority. They developed vast arsenals of nuclear weapons, including hydrogen bombs and long-range missiles. This led to a policy of deterrence, where the threat of mutual destruction was meant to prevent war. The Soviet launch of the Sputnik I satellite in 1957 intensified American fears of falling behind in this deadly competition for power.

A flood of refugees fled from communist East Germany to prosperous West Berlin, creating a crisis for the Soviets.

To stop this exodus, Soviet leader Khrushchev had the East German government build the Berlin Wall in August 1961.

This massive concrete barrier, lined with barbed wire and guard towers, physically separated the city. Note that the wall became the most potent and grim symbol of the Cold War’s division between democracy and communism.