Origins of the Cold War

The Cold War emerged from the breakdown of relations between two of the primary victors of World War II: the United States and Soviet Union, along with their respective allies in the Western Bloc and Eastern Bloc. This rivalry shaped the global order for the next four decades.

The roots of the Cold War can be traced back to tensions before World War II. The 1917 Russian Revolution and the Treaty of Brest-Litovsk deepened distrust among the Western Allies. Although the Soviet Union and Western powers worked together to defeat Nazi Germany, they did not trust each other.

After World War II, disagreements about the future of Europe became central. The Soviet Union set up governments in Eastern Europe that alarmed the United States and United Kingdom. The Marshall Plan in 1947 aimed to rebuild Europe and prevent the spread of communism, but the Soviet Union rejected it.

The first major military confrontation came with the Berlin Blockade of 1948–49. The Soviets tried to cut off Western access to Berlin, but the US and its allies flew supplies to West Berlin. By 1949, the Cold War was firmly in place with the creation of NATO.

Russian Revolution

Main articles: Russian Revolution and Allied intervention in the Russian Civil War

During World War I, Britain, France, and Russia were key allies. The United States joined them later. In 1917, a group called the Bolsheviks took control of Russia. Soon after, Germany, which was fighting in the war, moved troops into parts of Russia. This made the allies very unhappy. In early 1918, Russia agreed to a peace treaty with Germany called the Treaty of Brest-Litovsk. This treaty made many in the allied countries feel that Russia was helping Germany by letting German soldiers focus on fighting elsewhere.

Because of this, the allies sent money and some troops to support groups in Russia who opposed the Bolsheviks. The Bolsheviks, however, worked together as a strong team and eventually defeated their opponents, taking full control of Russia and some nearby areas. The country found itself alone, with other countries unwilling to work with its new government. The leader of Russia at the time, Vladimir Lenin, believed that countries around them were hostile and worked to keep those countries divided.

Interwar diplomacy (1918–1939)

Further information: International relations (1919–1939), Soviet Union–United States relations, and Russia–United Kingdom relations

The United States and the Soviet Union had very different ways of running their countries. The Soviet Union was controlled by one party, while the United States had many parties that competed against each other. These differences made it hard for them to trust each other.

In 1933, the United States finally recognized the Soviet Union as a country. This happened because earlier problems, like debts and disagreements about how countries should be run, had become less important. Both countries saw chances to trade more with each other.

Start of World War II (1939–1941)

Main articles: Molotov–Ribbentrop Pact and Soviet Union in World War II

Moscow felt upset with Western actions toward Adolf Hitler after the Munich Agreement in 1938. This agreement gave Nazi Germany some control of Czechoslovakia, and the Soviet Union was not invited to the talks.

In 1939, the Soviet Union talked with both Britain, France, and Germany about possible agreements. Later, the Soviet Union and Germany signed a Commercial Agreement. This agreement allowed them to trade military and civilian equipment for raw materials. They also signed the Molotov–Ribbentrop Pact, named after the foreign secretaries of both countries. This pact secretly planned to divide Poland and Eastern Europe between them.

Wartime alliance (1941–1945)

Further information: Diplomatic history of World War II

In 1941, Germany invaded the Soviet Union, breaking an earlier agreement. This led the Soviet Union to join forces with Britain, though the United States did not join until later that year after Japan attacked Pearl Harbor. Despite working together, the two sides did not always agree. For example, the Soviet leader wanted the Western Allies to open a second front against Germany sooner, but this did not happen until 1944.

During the war, there were many disagreements and misunderstandings between the Allies. Both sides had different ideas about how to keep peace after the war. The United States wanted a world where countries could work together through international groups. The Soviet Union, however, wanted to control areas near its borders to protect itself from future attacks.

See also: Operation Unthinkable and World War II Behind Closed Doors: Stalin, the Nazis and the West

Wartime conferences

See also: List of Allied World War II conferences

Several disagreements between the Western and Soviet leaders came from different views on meetings they had during and right after the war.

In late 1943, at the Tehran Conference, the Soviets were unhappy that the Western Allies had not yet opened a second front against Germany in Western Europe. The Allies also discussed the situation in Iran, where both the British and Soviets had troops.

At the Yalta Conference in February 1945, the Allies tried to agree on plans for after the war, but they could not fully agree on important issues like the future of Germany and Poland.

At the Second Quebec Conference in September 1944, Churchill and Roosevelt discussed plans for Germany after the war, including making it more focused on farming rather than industry.

Some historians think the Cold War began when the US made a separate agreement with a German general in 1945, which the Soviet Union was not part of.

Potsdam and the atomic bomb

Main articles: Potsdam Conference, Nuclear weapon, and Nuclear arms race

At the Potsdam Conference in July 1945, the Allies met to decide what to do with defeated Germany. The new US President, Harry Truman, was different from his predecessor and took a tougher stance toward the Soviet Union. The US had developed atomic bombs and used them against Japan, which upset the Soviet leader Stalin. The end of aid from the US to the Soviet Union after Germany surrendered also caused tension.

Creation of the Eastern Bloc

Further information: Percentages agreement, Cominform, Comecon, and Iron Curtain

After World War II, several countries in Eastern Europe came under the influence of the Soviet Union. This happened partly because of secret agreements made during the war and because the Soviet military was present in these areas. Leaders in countries like Romania, Bulgaria, Albania, and Yugoslavia began to support communist ideas, which worried countries like the United Kingdom and the United States.

The Soviet Union wanted to protect its borders by setting up governments that followed communist ideas in nearby countries. This led to changes in how these countries were ruled and their economies were managed. Many people tried to move to the west, but new rules made it very hard to leave.

Origins of containment

Further information: Containment

"Long Telegram" and "Mr. X"

Main article: X Article

As World War II was ending, some important people in the United States became worried about the Soviet Union. One of them, Averell Harriman, the US Ambassador in Moscow, felt let down by what he saw as the Soviet Union breaking promises about Poland.

In February 1946, George F. Kennan, who worked at the US Embassy in Moscow, sent a detailed message explaining why the Soviet Union did not want to join the World Bank or the International Monetary Fund. This message, called the Long Telegram, described how the Soviet Union made decisions and why they acted the way they did.

"Iron Curtain" speech

Main article: Iron Curtain

On March 5, 1946, Winston Churchill gave a famous speech in which he said that an "iron curtain" had come down across Europe, separating the East from the West.

Morgenthau and Marshall Plans

Further information: Morgenthau Plan, Marshall Plan, and Czechoslovak coup d'état of 1948

After losing many people in World War II, the Soviet Union wanted to make sure Germany could not start another war. The United States had plans to keep Germany weak, but later changed its mind. In 1947, General George Marshall became the US Secretary of State and worked on plans to help Europe recover, including Germany.

Greece and Italy

Main article: Greek Civil War

In Greece, there was a civil war, and the United States and Britain worked to support groups that were not communist. In Italy, Western Allies met with German representatives to prevent communist groups from taking control after the war.

Soviet military perspective

The Soviet military focused on defending the Soviet Union. They saw the formation of NATO in 1949 as a big threat and prepared their forces to respond. They kept strong military forces in Eastern Europe and formed their own alliance, the Warsaw Pact, to counter NATO.

Other regions

The Cold War happened all around the world, but it looked a little different outside Europe. In Africa, countries were becoming independent in the 1950s. The United States and the Soviet Union tried to support friendly governments in these new countries.

Latin America

During World War II, the United States had good support in Latin America, except in Argentina. After 1947, the United States tried to get Latin American countries to oppose communism. Many were slow to agree—for example, only Colombia sent soldiers to help in the Korean War. The Soviet Union was weak in Latin America at first, only making trade deals with Argentina and Mexico. Later, in the late 1950s, it built relationships with more countries. The United States worried about possible communist threats and worked to stop them. It supported anti-communist groups and gave money to help economies grow. In 1954, the United States said that any communist government in Latin America was a danger. That year, with help from the United States, Guatemala changed its government. In 1962, Cuba was identified as a communist country and removed from a group of American nations.

Asia-Pacific

After World War II, British Malaya faced conflict as British forces fought against groups that wanted independence. In British Hong Kong, there was unrest after the war ended.

Australia joined the Cold War in 1950 by sending forces to the Korean War right after the United States did. Australia made a military agreement with the United States and New Zealand called ANZUS in 1951. At first, Australia was very upset with Japan because of World War II, but Japan became an ally in the Cold War.

China

After many years of fighting, the Chinese Communist Party led by Mao Zedong took control of mainland China in 1949. The leaders of the old government escaped to Taiwan. The United States tried to help both sides work together, but they couldn’t. When the Korean War began, the United States gave more support to Taiwan, while China helped North Korea.

Vietnam

Vietnam was fighting over its future after France and Japan left in 1945. The communist group, led by Ho Chi Minh, fought against French forces. China and the Soviet Union supported Ho Chi Minh’s side, while the United States supported the other side. Vietnam’s struggles became part of the bigger Cold War conflicts.

Middle East

Iran had tensions between the Soviet Union and the Western countries after World War II. The Soviet Union supported areas in northern Iran, but later withdrew, and Iran stayed aligned with Western countries.

The long conflict between Arab nations and Jewish people continued after 1945. Both the Soviet Union and the United States supported the creation of Israel in 1948. Later, the Soviet Union started supporting Arab countries instead. The Middle East remained a complicated area, but it wasn’t a main cause of the Cold War. By the 1950s, Arab nationalism in Egypt became important. The Soviet Union grew closer to Egypt, while the United States formed alliances including the Baghdad Pact with Iran, Iraq, Pakistan, Turkey, and the United Kingdom.

Historians on the causes of the Cold War

Main article: Historiography of the Cold War

Many historians believe the Cold War began right after World War II, but others think it started much earlier, with the October Revolution in Russia in 1917. At that time, the Bolsheviks took control and formed a new government. Their leader, Lenin, felt surrounded by enemies and worked to support revolutionary movements around the world through an organization called the Communist International. However, these efforts did not succeed.

Some historians argue that distrust between the Soviet Union and Western countries went back even further. They point to events during and after World War I, when Western powers were worried about the spread of communist ideas. After World War II, tensions grew stronger with new conflicts, weapons, and participants.

The term "Cold War" became popular in 1947, when a US leader used it to describe the growing rivalry between the United States and the Soviet Union. Historians still debate who was responsible for this breakdown in relations after World War II and whether it could have been avoided. Some believe the Soviet Union was to blame, while others point to the United States. Still others think it was a mix of misunderstandings, political differences, and personal conflicts between leaders like Harry Truman and Stalin.