Oleg Vladimirovich Penkovsky

Table of Contents

Introduction References & Edit History Quick Facts & Related Topics

Oleg Vladimirovich Penkovsky

Q: What was the Cold War?

The Cold War was an ongoing political rivalry between the United States and the Soviet Union and their respective allies that developed after World War II . This hostility between the two superpowers was first given its name by George Orwell in an article published in 1945. Orwell understood it as a nuclear stalemate between “super-states”: each possessed weapons of mass destruction and was capable of annihilating the other. The Cold War began after the surrender of Nazi Germany in 1945, when the uneasy alliance between the United States and Great Britain on the one hand and the Soviet Union on the other started to fall apart. The Soviet Union began to establish left-wing governments in the countries of eastern Europe, determined to safeguard against a possible renewed threat from Germany. The Americans and the British worried that Soviet domination in eastern Europe might be permanent. The Cold War was solidified by 1947–48, when U.S. aid had brought certain Western countries under American influence and the Soviets had established openly communist regimes. Nevertheless, there was very little use of weapons on battlefields during the Cold War. It was waged mainly on political, economic, and propaganda fronts and lasted until 1991.

Q: How did the Cold War end?

The Cold War came to a close gradually. The unity in the communist bloc was unraveling throughout the 1960s and ’70s as a split occurred between China and the Soviet Union . Meanwhile, Japan and certain Western countries were becoming more economically independent. Increasingly complex international relationships developed as a result, and smaller countries became more resistant to superpower cajoling. The Cold War truly began to break down during the administration of Mikhail Gorbachev , who changed the more totalitarian aspects of the Soviet government and tried to democratize its political system. Communist regimes began to collapse in eastern Europe, and democratic governments rose in East Germany , Poland , Hungary , and Czechoslovakia , followed by the reunification of West and East Germany under NATO auspices. Gorbachev’s reforms meanwhile weakened his own communist party and allowed power to shift to the constituent governments of the Soviet bloc. The Soviet Union collapsed in late 1991, giving rise to 15 newly independent nations, including a Russia with an anticommunist leader.

Q: Why was the Cuban missile crisis such an important event in the Cold War?

In the late 1950s, both the United States and the Soviet Union were developing intercontinental ballistic missiles . In 1962 the Soviet Union began to secretly install missiles in Cuba to launch attacks on U.S. cities. The confrontation that followed, known as the Cuban missile crisis , brought the two superpowers to the brink of war before an agreement was reached to withdraw the missiles. The conflict showed that both superpowers were wary of using their nuclear weapons against each other for fear of mutual atomic annihilation. The signing of the Nuclear Test-Ban Treaty followed in 1963, which banned aboveground nuclear weapons testing. Still, after the crisis, the Soviets were determined not to be humiliated by their military inferiority again, and they began a buildup of conventional and strategic forces that the United States was forced to match for the next 25 years.

Soviet officer

Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Apr 19, 2025 • Article History

Quick Facts

Born:: April 23, 1919, Vladikavkaz, Russia

Died:: May 1963?, U.S.S.R.

See all related content

Oleg Vladimirovich Penkovsky (born April 23, 1919, Vladikavkaz, Russia—died May 1963?, U.S.S.R.) was a senior Soviet military intelligence officer who was convicted of spying for the United Kingdom and the United States. He was probably the West’s most valuable double agent during the Cold War.

Penkovsky joined the Soviet Red Army in 1937 and served as an artillery officer in World War II, being severely wounded in 1944. He attended the prestigious Frunze Military Academy in 1945–48. In 1949 Penkovsky transferred from the regular army to the Soviet army intelligence directorate (GRU). After attending the Military Diplomatic Academy (1949–53), he became an intelligence officer, serving primarily in Moscow. By 1960 he had become a colonel in the GRU and deputy chief of the foreign section of the State Committee for the Coordination of Scientific Research (1960–62), in which post his task was to collect scientific and technical intelligence on the United States, Britain, and other Western countries.

Penkovsky had in the meantime become increasingly disillusioned with the Soviet system, particularly with the leadership of Nikita Khrushchev. In April 1961, through Greville M. Wynne, a British businessman, he offered his services to British intelligence. Between April 1961 and August 1962 Penkovsky passed more than 5,000 photographs of classified military, political, and economic documents to British and U.S. intelligence forces. The information he provided on the Soviets’ relatively weak capability in long-range missiles proved invaluable to the United States before and during the Cuban missile crisis of October 1962. Penkovsky was in fact arrested by the Soviets on Oct. 22, 1962, at the height of that crisis, after they realized that highly classified information was leaking to the West.

Communism - mosaic hammer and sickle with star on the Pavilion of Ukraine at the All Russia Exhibition Centre (also known as VDNKh) in Moscow. Communist symbol of the former Soviet Union. USSR

Cold War

international politics

Written and fact-checked by The Editors of Encyclopaedia Britannica

Article History

Quick Facts

Date:: 1947 - 1991

Participants:: North Atlantic Treaty Organization; Soviet Union; United States; Warsaw Treaty Organization

Context:: international relations

Major Events:: Bay of Pigs invasion; Nuclear Test-Ban Treaty; Strategic Arms Limitation Talks; Berlin crisis of 1961; collapse of the Soviet Union

Key People:: Dean Acheson; John Foster Dulles; John F. Kennedy; Kim Philby; Ronald Reagan

See all related content

What was the Cold War?

How did the Cold War end?

Why was the Cuban missile crisis such an important event in the Cold War?

News •

The UK seeks to send a message to Moscow as it outlines higher defense spending • June 1, 2025, 7:40 AM ET (AP)

Trump brands his opponents as 'communists,' a label loaded with the baggage of American history • May 4, 2025, 8:59 PM ET (AP)

Cold War, the open yet restricted rivalry that developed after World War II between the United States and the Soviet Union and their respective allies. The Cold War was waged on political, economic, and propaganda fronts and had only limited recourse to weapons. The term was first used by the English writer George Orwell in an article published in 1945 to refer to what he predicted would be a nuclear stalemate between “two or three monstrous super-states, each possessed of a weapon by which millions of people can be wiped out in a few seconds.” It was first used in the United States by the American financier and presidential adviser Bernard Baruch in a speech at the State House in Columbia, South Carolina, in 1947.

A brief treatment of the Cold War follows. For full treatment, see international relations.

Origins of the Cold War

Following the surrender of Nazi Germany in May 1945 near the close of World War II, the uneasy wartime alliance between the United States and Great Britain on the one hand and the Soviet Union on the other began to unravel. By 1948 the Soviets had installed left-wing governments in the countries of eastern Europe that had been liberated by the Red Army. The Americans and the British feared the permanent Soviet domination of eastern Europe and the threat of Soviet-influenced communist parties coming to power in the democracies of western Europe. The Soviets, on the other hand, were determined to maintain control of eastern Europe in order to safeguard against any possible renewed threat from Germany, and they were intent on spreading communism worldwide, largely for ideological reasons. The Cold War had solidified by 1947–48, when U.S. aid provided under the Marshall Plan to western Europe had brought those countries under American influence and the Soviets had installed openly communist regimes in eastern Europe.

The struggle between superpowers

North Atlantic Treaty OrganizationU.S. Secretary of State Dean Acheson (center) calling to order a meeting of the North Atlantic Treaty Organization (NATO) on September 15, 1950.

The Cold War reached its peak in 1948–53. In this period the Soviets unsuccessfully blockaded the Western-held sectors of West Berlin (1948–49); the United States and its European allies formed the North Atlantic Treaty Organization (NATO), a unified military command to resist the Soviet presence in Europe (1949); the Soviets exploded their first atomic warhead (1949), thus ending the American monopoly on the atomic bomb; the Chinese communists came to power in mainland China (1949); and the Soviet-supported communist government of North Korea invaded U.S.-supported South Korea in 1950, setting off an indecisive Korean War that lasted until 1953.

Cuban missile crisisAerial photograph of Medium Range Ballistic Missile (MRBM) Launch Site 1 near San Cristóbal, Cuba, taken on October 25, 1962.

Explore technological innovations of the Cold WarLearn about inventions that were created during the Cold War, such as the Internet and different kinds of military equipment.
See all videos for this article

How the Cold War contributed to antibiotic resistanceLearn more about how Cold War medical innovations led to antibiotic-resistant bacteria.
See all videos for this article

From 1953 to 1957 Cold War tensions relaxed somewhat, largely owing to the death of the longtime Soviet dictator Joseph Stalin in 1953; nevertheless, the standoff remained. A unified military organization among the Soviet-bloc countries, the Warsaw Pact, was formed in 1955; and West Germany was admitted into NATO that same year. Another intense stage of the Cold War was in 1958–62. The United States and the Soviet Union began developing intercontinental ballistic missiles, and in 1962 the Soviets began secretly installing missiles in Cuba that could be used to launch nuclear attacks on U.S. cities. This sparked the Cuban missile crisis (1962), a confrontation that brought the two superpowers to the brink of war before an agreement was reached to withdraw the missiles.

Wreckage of the U-2 spy plane shot down inside the Soviet Union in 1960. U-2 spy plane incident, U-2 affair, Cold War.

Britannica Quiz

Comprehension Quiz: Cold War

Nuclear Test-Ban TreatyU.S. Pres. John F. Kennedy signing the Nuclear Test-Ban Treaty, October 7, 1963.

The Cuban missile crisis showed that neither the United States nor the Soviet Union were ready to use nuclear weapons for fear of the other’s retaliation (and thus of mutual atomic annihilation). The two superpowers soon signed the Nuclear Test-Ban Treaty of 1963, which banned aboveground nuclear weapons testing. But the crisis also hardened the Soviets’ determination never again to be humiliated by their military inferiority, and they began a buildup of both conventional and strategic forces that the United States was forced to match for the next 25 years.

Soviet invasion of PragueCzechoslovaks confronting Soviet troops in Prague, August 21, 1968. Soviet forces had invaded Czechoslovakia to crush the reform movement known as the Prague Spring.

Throughout the Cold War the United States and the Soviet Union avoided direct military confrontation in Europe and engaged in actual combat operations only to keep allies from defecting to the other side or to overthrow them after they had done so. Thus, the Soviet Union sent troops to preserve communist rule in East Germany (1953), Hungary (1956), Czechoslovakia (1968), and Afghanistan (1979). For its part, the United States helped overthrow a left-wing government in Guatemala (1954), supported an unsuccessful invasion of Cuba (1961), invaded the Dominican Republic (1965) and Grenada (1983), and undertook a long (1954–75) and unsuccessful effort to prevent communist North Vietnam from bringing South Vietnam under its rule (see Vietnam War).