The Truman Doctrine marked the start of US containment strategy

Introduced in 1947, the Truman Doctrine pledged US support for nations resisting communism—starting with Greece and Turkey—and launched the containment policy that defined early Cold War strategy.

The Cold War (1947-1991) prompted the birth of NATO and the Soviet Warsaw Pact

The geopolitical rivalry between the United States and Soviet Union was considered “cold" because the two countries never directly engaged in military combat during the time period. This page from the Kennedy Presidential Library outlines the causes and major events of the early Cold War.

Wartime conferences exposed cracks in the US–Soviet alliance

At the Tehran, Yalta and Potsdam Conferences, Allied leaders coordinated WWII strategy—but deep disagreements over postwar Europe foreshadowed the Cold War. The USSR’s push for influence in Eastern Europe clashed with US and British calls for self-determination.

Churchill’s 1946 ‘Iron Curtain’ speech warned of growing Soviet domination

In a 1946 speech, Winston Churchill declared that an “Iron Curtain” had descended across Europe—dividing East from West. The address marked one of the first public acknowledgments of the emerging Cold War and coined the term that would define the conflict.

Propaganda became a key weapon in the US–Soviet Cold War

Both superpowers waged a global battle for hearts and minds through propaganda—using film, radio, art and education to promote their values. The US emphasized freedom and prosperity, while the USSR championed socialism and anti-imperialism.

US–Soviet hostility began long before the Cold War

US–Soviet tensions began decades before WWII. After the 1917 revolution, the US refused to recognize the Bolshevik regime and even sent troops to fight against it.

The Soviet Union had a similar sphere of influence policy during the Cold War—the Brezhnev Doctrine

Articulated in 1968, the Brezhnev Doctrine claimed the Soviet Union's right to intervene militarily in its satellite states to prevent any deviation from communist rule. It was used to justify the invasion of Czechoslovakia that same year and the invasion of Afghanistan in 1979.

James Monroe first outlined what became known as the 'Monroe Doctrine' during his 1823 Annual Message to Congress

President Monroe used his Annual Message to Congress to warn European powers against further colonization in the Western Hemisphere, asserting US opposition to foreign intervention and laying the foundation for a cornerstone of American foreign policy that remains to this day.

Cold War summary on a map

The Cold War spanned much of the world, going far beyond the main territories of the principal players: the US and the Soviet Union. This video map shows where the action took place, from the wars in Southeast Asia to the Suez Canal in Egypt.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

Learn about the history of the Monroe Doctrine

CBS Sunday Morning explores the origins of the Monroe Doctrine, tracing how a 19th-century warning against European intervention shaped US foreign policy and influenced America’s role in the Western Hemisphere for generations.

The Marshall Plan aimed to rebuild Europe and limit Soviet influence

Launched in 1948, the Marshall Plan provided over $12B (roughly $150B today) in US aid to help rebuild Western Europe. While framed as economic recovery, it also served as a Cold War tool—tying countries to the US and excluding the Soviet bloc.

An NSA analyst helped avert nuclear war during the Cuban Missile Crisis

In October 1962, NSA cryptographer Juanita Moody headed analysis of U‑2 surveillance data and urgently produced intelligence on Soviet missile deployments in Cuba. Her reports drove high-level US decision-making, and were critical to avoiding nuclear war during the Cuban Missile Crisis.

The Soviet Union explained

From 1922 to 1991, the Soviet Union spanned one-sixth of Earth’s landmass and housed nearly 300 million people. As the most significant test of Marxist governance, it sat at the center of the century’s defining struggle between capitalism and communism.

NATO was formed in 1949 to deter Soviet expansion, prevent European militarism, and encourage political integration.

The Monroe Doctrine promoted 4 core principles

Monroe outlined four positions: the US would not interfere in European conflicts; it would not disturb existing European colonies in the Americas; the Western Hemisphere was closed to new colonization; and any European attempt to control an independent American republic would be regarded as a threat to US security.

The term ‘McCarthyism’ was coined by a political cartoonist

In February 1950, Senator Joseph McCarthy infamously proclaimed that he had a list of communist State Department employees. The next month, cartoonist Herbert Block published a cartoon in the Washington Post featuring a reluctant elephant (the mascot of the Republican Party) being pushed to stand on a wobbly tower labeled “McCarthyism.”

How Stalin, Roosevelt, and Churchill shaped the postwar world

The Yalta Conference was a pivotal 1945 meeting between Allied leaders that helped shape the postwar global order and laid the groundwork for the founding of the United Nations.

Truman's decision to enter the Korean War without congressional authorization marked a major shift in presidential war powers

Rather than seeking a declaration of war, Truman sent troops to Korea under his own authority, citing the UN Charter and his role as commander in chief. The decision set a precedent that subsequent presidents have relied on ever since.

Cold War soft power helped sell the space race to the American public

The fear of Soviet dominance prompted the US to invest heavily in space, but public support was also crucial. This video shows how marketing, media, and "soft power" framed spaceflight as peaceful, aspirational, and worth the cost—helping sustain the space race at home.

The intellectual architect of the Monroe Doctrine was Secretary of State John Quincy Adams, not Monroe

Adams, the main foreign relations authority in the Cabinet, shaped the key parts of the Monroe Doctrine speech. He advocated for a unilateral American declaration to warn European powers, rejecting a potential joint statement with Britain favored by some Cabinet members.

Learn how the Soviets won the early space race

This video traces how Cold War arms competition transformed rocketry into a symbol of global power, following pioneers like Tsiolkovsky and von Braun through World War II and into the 1950s, culminating in the Soviet Union’s launch of Sputnik I in 1957.

Read an excerpt from the Monroe Doctrine, introduced in Monroe's 1823 address to Congress

On Dec. 2, 1823, President Monroe delivered his seventh annual message to Congress, now known as the State of the Union. One segment—warning European powers against interfering in the Western Hemisphere—became known as the Monroe Doctrine.

The Monroe Doctrine was designed to keep Europe out of the Americas

First articulated in 1823 by President James Monroe, the doctrine declared the Western Hemisphere off limits to European colonization. It has since been invoked to justify US military interventions in Latin America, from Teddy Roosevelt's takeover of Venezuela to George H.W. Bush's arrest of Panama's leader Manuel Noriega.

US–Cuba contentious relations began long before the Cold War

Long before the revolution and missile crisis, US involvement in Cuba stretched back over 150 years—rooted in slavery, sugar, and shifting imperial ambitions. This short video traces how cycles of intervention and neglect shaped the island’s modern history.

The Soviet Union’s surprising first atomic test ended the US nuclear monopoly

In 1949, the USSR successfully tested its first atomic bomb—ending the US monopoly on nuclear weapons and sparking an arms race that would define the Cold War.

The US intervened in Latin America to block communist influence during the Cold War

Fearing Soviet expansion, the US intervened across Latin America by backing coups, funding right-wing regimes, and supporting anti-communist militias—most notably in Cuba, Chile, Nicaragua and Guatemala.

The failed Bay of Pigs invasion led to the Cuban Missile Crisis, which brought the world to the brink of nuclear annihilation

Moscow's decision to deploy nuclear missiles in Cuba—just 90 miles from the US—pushed the world to the brink of nuclear war. To prevent future crises, both sides later set up a direct hotline and boosted arms-control diplomacy

Four Cold War hawks warn: Nuclear weapons still threaten the world

Despite the Cold War's end, the US and Russia still hold 95% of the world's nuclear weapons—many on hair-trigger alert. In this 2010 documentary, top former officials urge urgent action to reduce and eliminate the threat.

During the Cold War, the rules-based order was largely limited to the West

The Soviet Union and its allies operated outside the Bretton Woods institutions, meaning the postwar liberal order functioned as a regional rather than a truly global system. This changed with the USSR's collapse in 1991.

Cold War rivalries fueled fierce competition in international sports

From Olympic medal counts to hockey showdowns, the US and USSR used sports to showcase ideological superiority. Athletic victories were framed as proof that each system—capitalist or communist—produced stronger, more disciplined citizens.

The US and the USSR backed opposing sides in dozens of proxy wars during the Cold War

To avoid direct confrontation, the superpowers supported rival factions in conflicts around the world—including in Korea, Vietnam, Angola, and Afghanistan.

A digital archive of the Korean War

The Korean War largely shaped the evolution of the Cold War in Asia. Explore the Wilson Center’s digital collection of primary sources—including essays, profiles, popular documents, and a timeline—to learn about the Korean War. In 1945, the...

A primer on the president's nuclear football

During the Cold War, the United States and the USSR were forced to prepare for a nuclear strike at a moment's notice, leading to a new innovation: the so-called "football" (known as the chemodanchik in Russia), a bag containing nuclear strike plans, authentication codes, and likely a communication device, which attended the country's leader wherever they went. This easy-to-read piece breaks down the history and lore around the high-stakes quirk in nuclear governance.

Spies working on the Manhattan Project propelled the Soviet bomb program

Soviet infiltration—most notably by Klaus Fuchs—smuggled detailed implosion-design and hydrogen‑bomb data from Los Alamos to Moscow, cutting the USSR’s development time by at least a year and enabling their first atomic test in August 1949.

President Trump invoked the Monroe Doctrine in 2025, announcing a new 'Trump Corollary'

On Dec. 2, 2025, the 202nd anniversary of the doctrine, President Donald Trump issued a proclamation reaffirming US "dominance" in the Western Hemisphere. His administration's national security strategy officially codified the "Trump Corollary," stating that the US would prevent non-hemispheric powers from gaining strategic influence in the Americas.

Sartre eventually denounced communism

The French philosopher was a long-time ardent supporter of communism and the USSR. He finally spoke out against the movement with the 1956 Soviet invasion of Hungary, saying that the move was "made possible by 12 years of terror and imbecility."

Designs for the Hubble Space Telescope were based on Cold War spy satellites

By incorporating elements of the KH-11 KENNEN reconnaissance satellites, NASA could incorporate existing classified manufacturing expertise and infrastructure from the intelligence community to expedite the research project.