The Cold War was a conflict between the United States of America (and its allies) and the Soviet Union (and its allies). The conflict began in the mid-1940s, just after the end of the Second World War and ended in the early 1990s with the collapse of the Soviet Union. It is called the Cold War because the USA and USSR never fought each other directly.

Key events in the cold war include the Berlin airlift, the Korean War, the Cuban Missile Crisis, the crushing of revolutions in Hungary and Czechoslovakia, détente, the Vietnam War, and the fall of the Berlin Wall.

This article gives a summary of the Cold War. To find out more please click the links contained in the article.

When did the Cold War start?

The Cold War began at the end of the second world war.

The USA and USSR had very different ideologies – ways of looking at the world. The United States was a capitalist economy, and the Soviet Union had a communist economy. They each wanted to demonstrate to the world that their economic and political models were superior. They were also the two largest military powers in the world, with competing geopolitical interests.

Although they were allies during the war and fought to defeat the Axis powers, their alliance was one of convenience. As the war came to a close they both began to position themselves for world that would follow.

As the war against Japan drew to a close, the United States dropped atomic bombs on the cities of Hiroshima and Nagasaki. Although primarily aimed at forcing the Japanese to surrender, it is likely that US President Truman also wanted to demonstrate to the Soviet Union the extent of US military power.

At the end of the war US and British troops occupied most of Western Europe and Soviet troops occupied most of Eastern Europe. They agreed at the Yalta Conference that the defeated Germany should be partitioned into four zones – one each to be administered by the US, Britain, France and the Soviet Union.

It wasn’t long before Germany was formally divided into two countries and the whole of Europe was split into two – the US with its NATO allies in the West and the USSR with its Warsaw Pact allies in the East.

Churchill memorably described Europe’s split as an Iron Curtain:

“From Stettin in the Baltic to Trieste in the Adriatic an ”Iron Curtain“ has descended across the continent. Behind that line lie all the capitals of the ancient states of Central and Eastern Europe. Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest and Sofia; all these famous cities and the populations around them lie in what I must call the Soviet sphere, and all are subject, in one form or another, not only to Soviet influence but to a very high and in some cases increasing measure of control from Moscow.”

Conflict in the Cold War

The United States quickly settled on a policy of Containment for dealing with the Soviet Union. Containment was heavily influenced by the thoughts of George Kennan, a diplomat stationed in Moscow. In his ‘Long Telegram’ he explained that a neurotic Soviet Union, afraid of the outside world, would seek to agressively expand its reach. The best way to contain this, he argued, was through:

“patient but firm and vigilant containment of Russian expansive tendencies… the adroit and vigilant application of counterforce at a series of constantly shifting geographical and political points, corresponding to the shifts and manoeuvers of Soviet policy.”

One of the key pillars of the containment policy was the US Marshall Plan. By giving aid to European governments the US hoped that Europe’s economy would quickly rebuild, providing stability across the continent. Marshall Plan aid was offered to the Soviet Union but it turned down the offer – on its own behalf and on behalf of most Eastern European countries.

The Soviet Union felt that the introduction of a US-backed Deutschmark in Western Germany was a step to far and, in June 1948, began a blockade of West Berlin.

For almost a year the US and its Western allies airlifted supplies into the isolated city. The blockade was lifted in May 1949, but it had given both sides an opportunity to test the other’s resolve.

Cold War conflict expanded outside of Europe in June 1950, when North Korea invaded South Korea. The United States and Soviet China were gradually drawn into direct military conflict, and the intense three year war that followed cost millions of lives. The Soviet Union managed to keep at arms length from the conflict, although it did provide massive amounts of financial and military assistance to both North Korea and China. It was only shortly after Stalin’s death in 1953 that a ceasefire could be agreed.

After the brush with hot war in Korea, the Cold War stabilised somewhat. Both the US and USSR invested heavily in expanding their military forces, particularly their nuclear arsenals. They also began actively courting other world governments, particularly in the Third World. The Sino-Soviet alliance (between China and the USSR) dissolved, as both sought to be seen as the leading communist state.

The Cuban Missile Crisis took place in 1962. It was the most dangerous flashpoint of the Cold War. Nikita Krushchev, the Soviet leader, tried to take advantage of Fidel Castro’s communist revolution in Cuba, the first in the Americas, to gain a foothold just off the US coast. Over several months it began to install nuclear missiles in Cuba.

The US, under President John F Kennedy, responded with a naval blockade of the island. Krushchev ultimately backed down, but not before the world realised it had just tetered on the brink of an all out nuclear war.


The Cuban Missile Crisis acted, in many ways, as a reality check for the leaders of both the Soviet Union and the United States.

Under new leaders (Kennedy was assasinated in 1963 and Krushchev was forced to ‘retire’ in 1964) the world’s superpowers began to normalise relations. They recognised that direct confrontation, combined with miscommunication, risked disaster. To help resolve any conflicts a hotline was installed to directly connect the Kremlin and the White House. The hotline is popularly known as the ‘red telephone’, but it was actually just a simple telegraph machine.

The focus of superpower competition shifted instead to the Third World. Vast amounts were spent wooing the leaders of countries in Africa, the Middle East and Asia. Many Third World leaders quickly became adept at playing the two superpowers off against each other and pledging allegiance to the one that offered the most financial or military support. The Soviet Union managed to avoid becoming entangled in any serious military conflicts, but the US quickly became bogged down in the Vietnam War.

Détente, which began in 1969, was perhaps the high point in relations between the USA and USSR. Initiated by US President Richard Nixon and continued by his successor Gerald Ford, détente aimed to thaw out relations with the Soviet Union. Brezhnev embraced the idea enthusiastically, probably because he saw it as an opportunity to give the Soviet Union breathing space that it could use to build its economy and global influence.

The Soviet and American leaders held several high profile summits in the 1970s, many of which led to the signing of treaties limiting each country’s arsenal of biological and nuclear weapons. Other treaties, such as the Helsinki Accords, focused on human rights. Co-operation even extended into space where, in July 1975, the Apollo and Soyuz spacecraft docked together in Earth orbit.

When did the Cold War end?

After nearly a decade of détente tensions began to rise again. In 1979 Soviet troops invaded Afghanistan to support the new, but struggling, communist government there.

The US under President Ronald Reagan began to ratchet up the pressure on its Soviet adversary. Describing the USSR as an ‘Evil Empire’ the US began to spend heavily on arms, notably the ‘Star Wars’ missile defense programme. At the same time – probably as a reaction to the perceived weakness of the previous Carter administration – the US began to pursue a more assertive foreign policy, providing financial and military aid to anti-communist forces across the globe.

After years of economic and political stagnation, the USSR found it difficult to respond to this new assertiveness. It couldn’t afford to match US military spending and was under pressure from its own people (and people in its Eastern European satellite states) to improve the domestic economy and give them more political freedoms.

Mikhail Gorbachev attempted to reform the Soviet economy and bureaucracy, as well as to introduce direct elections. These reforms were called Perestroika (restructuring) and Glasnost (openness). Many of the reforms, though, simply encouraged people to ask for – and demand – new freedoms.

In 1989 communist regimes across Eastern Europe fell, as you can see in this BBC timeline. The most striking symbol of this collapse of communist authority was the fall of the Berlin Wall. Most of the revolutions of 1989 were peaceful. Romania was the only Warsaw Pact country that violently overthrew its communist government.

Two years later, in 1991, communist hardliners in Moscow attempted a coup. When the August Coup plotters failed to gather widespread support – thanks in part to the energetic opposition of Boris Yeltsin – it was only a matter of time before the USSR itself collapsed. When the Soviet Union was formally dissolved in 1991, the Cold War came to an end.