The Cold War and the European Union

TL;DR. After the Second World War ended in 1945, Europe was split in two. The western half became democratic and capitalist, tied to the United States. The eastern half came under the control of the Soviet Union and became communist. This standoff, which lasted from the late 1940s until about 1991, is called the Cold War, because the two sides built huge armies and nuclear weapons but never fought each other directly in open war. Two rival alliances faced off: NATO, led by the United States, in the West, and the Warsaw Pact, led by the Soviet Union, in the East. Meanwhile Western Europe began joining together for trade and peace, a project that grew into the European Union. When communism collapsed between 1989 and 1991, the divide ended, and much of the former East joined the West. In recent years Russia, under Vladimir Putin, has tried to reassert its power, most dramatically by invading Ukraine in 2022.

Key takeaways

• After 1945 Europe was divided by what Winston Churchill called the "Iron Curtain": a democratic, capitalist West and a communist East controlled by the Soviet Union.
• The two camps formed military alliances. NATO (1949) was the United States led Western alliance. The Warsaw Pact (1955) was the Soviet led Eastern bloc.
• Germany, and especially the city of Berlin, sat on the front line. The Berlin Wall (1961 to 1989) became the most famous symbol of the divide.
• Western Europe knit itself together through trade, starting in the 1950s and growing into the European Union, partly to make another war between France and Germany unthinkable.
• Communism in Eastern Europe collapsed in 1989, the Berlin Wall fell, Germany reunified in 1990, and the Soviet Union dissolved in 1991.
• Today Europe faces new strains, including Britain leaving the EU and Russia's 2022 invasion of Ukraine, which much of the world has condemned.

Main events at a glance

A continent split in two

The Second World War ended in Europe in May 1945. Germany, which had started the war and committed enormous atrocities, was defeated and occupied. The victorious powers were an unusual partnership: the Western democracies (above all the United States and the United Kingdom) on one side, and the Soviet Union, a communist state led by Joseph Stalin, on the other. They had fought together against Nazi Germany, but they did not trust each other, and once the common enemy was gone, that distrust grew quickly.

The disagreement was partly about ideas and partly about power. The Western countries believed in democracy, where people vote in free elections among competing parties, and in capitalism, an economic system in which businesses are mostly privately owned and prices are set by markets. The Soviet Union believed in communism, a system in which a single party rules and the state controls the economy in the name of the working class. Each side feared the other would try to spread its system across the world.

As the war ended, Soviet armies occupied most of Eastern Europe, while Western armies held the West. Rather than withdraw, the Soviet Union installed communist governments loyal to Moscow across the countries it controlled, including Poland, Hungary, Czechoslovakia, Romania, Bulgaria, and the eastern part of Germany. A line ran across the continent, separating the Soviet controlled East from the democratic West. In 1946 the British leader Winston Churchill gave that line its famous name when he said an "Iron Curtain" had descended across Europe. The phrase stuck because it captured the feeling of a wall, real and imagined, cutting families, cities, and the whole continent in two.

Don't be confused: "the West" and "the East" here are political camps, not just compass directions. During the Cold War, "the West" meant the United States and its democratic, capitalist allies, and "the East" (or the "Eastern bloc") meant the Soviet Union and the communist states under its control. A country could sit in the geographic east of Europe but, in this sense, belong to neither camp. The labels describe which political and military side a country was on, not where it sat on a map.

Two systems, two alliances

To understand the Cold War, it helps to be very clear about who stood with whom, because the two sides built formal military alliances.

In the West, the United States chose not to retreat into isolation as it had after the First World War. In 1947 it announced the Marshall Plan, a large program of American money to help rebuild war-shattered Western Europe. The aim was both generous and strategic: a prosperous Europe would be more stable and less tempted by communism. Then, in 1949, the United States, Canada, and a group of Western European countries founded the North Atlantic Treaty Organization, or NATO. NATO is a military alliance built on a simple promise: an attack on one member is treated as an attack on all. In plain terms, the United States pledged to defend Western Europe, including with its nuclear weapons.

In the East, the Soviet Union answered in 1955 by creating the Warsaw Pact, a military alliance binding together the communist states of Eastern Europe under Soviet command. So by the mid-1950s, the line down Europe was not just political but military: NATO on one side, the Warsaw Pact on the other, each with large armies facing each other in the center of the continent.

The two superpowers, the United States and the Soviet Union, never fought each other directly, and that is the key to the word "cold." Both built terrifying arsenals of nuclear weapons, enough to destroy each other many times over. The grim logic that kept the peace became known as "mutually assured destruction": neither side could attack without being destroyed in return. Instead of fighting directly, they competed in other ways: through spying, propaganda, a race to build weapons, a race to reach space, and "proxy wars" in other parts of the world, where each side backed opposing local forces.

Germany and Berlin: the front line

Nowhere was the division sharper than in Germany. After the war the country was split into zones run by the occupying powers. The American, British, and French zones merged into a democratic country, the Federal Republic of Germany, usually called West Germany. The Soviet zone became a communist state, the German Democratic Republic, or East Germany. One nation was now two countries on opposite sides of the Iron Curtain.

The city of Berlin made things even more tangled. Berlin sat deep inside East Germany, but it too had been divided among the four powers, so West Berlin was an island of the democratic West surrounded by communist territory. This odd arrangement led to one of the first great crises of the Cold War. In 1948 the Soviet Union cut off all road and rail routes into West Berlin, hoping to force the Western powers out by starving the city. This was the Berlin Blockade. Rather than give up or fight their way in, the Western allies flew in food, coal, and supplies, day after day, in a vast operation called the Berlin Airlift. Planes landed around the clock for nearly a year until the Soviets lifted the blockade in 1949.

The deepest scar came in 1961. So many East Germans were escaping to the West through Berlin, often the young and skilled, that the East German government, with Soviet backing, sealed the border overnight and built the Berlin Wall. The Wall was a heavily guarded barrier of concrete and wire that cut straight through the city, separating neighbors, friends, and families. Guards were ordered to shoot people trying to flee, and many died attempting to cross. For nearly thirty years the Berlin Wall stood as the most powerful symbol of a divided Europe: a place where you could literally see the line between the two systems.

Life in the Eastern Bloc

It is important to describe life in the communist East plainly, without either the harsh caricatures of Western propaganda or the rosy claims of official Soviet sources. The communist states of Eastern Europe shared some common features.

Politically, they were one-party states. Only the Communist Party was allowed to hold real power, elections offered no genuine choice, and open opposition was not tolerated. Economically, they used planned economies: instead of markets setting prices and businesses deciding what to make, government planners decided what factories produced, what shops sold, and what things cost. This system did deliver some things, such as guaranteed jobs, free schooling, and basic housing and health care. But it often struggled to produce enough consumer goods, leading to shortages and long queues, and it tended to lag behind the West in living standards and technology over time.

To stay in control, these governments relied on secret police and informers. The most famous was East Germany's Stasi, which built enormous files on ordinary citizens, often using neighbors and even family members as informants. Speaking against the system, trying to leave, or organizing independently could cost people their jobs, their freedom, or worse.

When people pushed back, Soviet power was used to keep the bloc in line. In East Germany in 1953, workers protested and were put down. In Hungary in 1956, a popular uprising tried to break free of Soviet control and was crushed by Soviet tanks, with thousands killed. In Czechoslovakia in 1968, a reform movement known as the Prague Spring tried to build "socialism with a human face," loosening censorship and allowing more freedom. The Soviet Union and its Warsaw Pact allies sent in troops to stop it. These crushed uprisings showed both the deep desire for change in the East and the limits the Soviet Union placed on it.

Don't be confused: socialism and communism are related but not identical. "Socialism" is a broad idea that society should share ownership and reduce inequality, and many democratic countries in the West adopted moderate, voluntary versions, such as public health care, while keeping free elections and private business. "Communism," as practiced in the Soviet bloc, was a far more total system in which a single party controlled the state and the whole economy. So a Western European "socialist" party operating in a democracy was a very different thing from the Communist Party that ruled a one-party Eastern state.

The empires dissolve: decolonization

While Europe was dividing into two camps at home, it was also losing control of its overseas empires. Before the war, several European countries, especially Britain and France, but also Belgium, the Netherlands, Portugal, and others, had ruled vast colonies across Asia, Africa, and elsewhere. The war weakened the European powers and strengthened independence movements in the colonies, where many people had concluded that they should govern themselves.

In the decades after 1945, one colony after another became independent, a process called decolonization. India and Pakistan gained independence from Britain in 1947. Much of Africa became independent during the 1950s and 1960s. Some transitions were relatively peaceful, while others, such as in Algeria and parts of Southeast Asia, involved long and bloody wars. By the 1970s the old European empires had largely dissolved. This reshaped not only the wider world but Europe itself, as people from former colonies migrated to Europe, helping to make countries like Britain and France more diverse.

Building peace: the road to the European Union

In Western Europe, leaders drew a hard lesson from two world wars: France and Germany had fought each other again and again, and the whole continent had paid the price. The answer they reached for was surprising. Instead of trying to keep Germany weak, they tried to tie the old enemies so tightly together through trade that war between them would become not just unwise but almost impossible.

The first step came in 1951, when France, West Germany, Italy, Belgium, the Netherlands, and Luxembourg pooled control of their coal and steel industries in the European Coal and Steel Community. Coal and steel were the raw materials of weapons, so sharing them was a deliberate way to make rearming for war very difficult. The experiment worked well enough that the same six countries went further. In 1957 they signed the Treaty of Rome, creating the European Economic Community, or EEC, often called the "Common Market." Its goal was to let goods, and eventually people and money, move freely across borders, so that the economies grew together.

Over the following decades the community grew, both in members and in ambition. More countries joined, including the United Kingdom in 1973. In 1993 the project took its modern form and name: the European Union, or EU. The EU is more than a trade zone. It has its own parliament, courts, and rules, and member states agree to share some decisions in return for the benefits of working together. Later steps deepened the bond further. The Schengen agreement removed passport checks at many internal borders, so people could travel between member countries as easily as between regions of one country. And in 2002 a shared currency, the euro, came into everyday use in many member states, replacing national currencies like the French franc and the German mark.

Don't be confused: NATO and the EU are two different things. NATO is a military alliance, including the United States and Canada, whose job is collective defense: members promise to protect one another. The EU is a political and economic union of European countries, focused on trade, law, and cooperation, with no North American members. Many countries belong to both, but they are separate organizations with separate purposes. A country can be in one without being in the other.

The Cold War ends

By the 1980s the Soviet system was straining. Its economy had fallen far behind the West, the cost of the arms race was crushing, and people across the Eastern bloc were increasingly frustrated. In 1985 a new and younger Soviet leader, Mikhail Gorbachev, came to power and tried to fix the system rather than abandon it. He launched two reforms that became famous by their Russian names: glasnost, meaning "openness," which allowed more honest public discussion, and perestroika, meaning "restructuring," which tried to loosen the rigid economy. Crucially, Gorbachev also signaled that the Soviet Union would no longer send tanks to prop up the communist governments of Eastern Europe.

That signal changed everything. Once people in the East realized Moscow would not crush them, change came with stunning speed. The year 1989 is one of the most remarkable in modern history. In country after country, communist governments fell, mostly through peaceful protest. Poland held partly free elections. Hungary opened its border. And in November 1989, after weeks of mass demonstrations, the East German government suddenly allowed people to cross to the West. Crowds climbed onto the Berlin Wall and began tearing it down. The single most famous symbol of the divided continent was opened by ordinary people, and the images circled the world.

The momentum was unstoppable. In 1990 East and West Germany reunified into a single democratic country. Across Eastern Europe, the new governments turned toward democracy and market economies. Then, in 1991, the Soviet Union itself broke apart. Its fifteen republics became independent countries, including Russia, Ukraine, and the three Baltic states of Estonia, Latvia, and Lithuania. With the Soviet Union gone, the Warsaw Pact dissolved, and the Cold War was over. After more than forty years, the Iron Curtain had vanished.

Europe after the Cold War

The end of the Cold War opened a hopeful new chapter. Many former communist countries wanted to join the Western institutions they had been cut off from. Over the following years, the EU enlarged eastward: in 2004 a large group of countries, most of them formerly communist, including Poland, Hungary, the Czech Republic, and the Baltic states, joined the European Union, with more following later. Many of these countries also joined NATO, seeking the security of the Western alliance. For a time it seemed Europe might become "whole and free," united under democracy and cooperation.

But the post-Cold War decades brought their own strains. A global financial crisis after 2008 hit the shared euro currency hard, especially in countries like Greece. A migration crisis in 2015, driven largely by war in Syria, saw large numbers of refugees and migrants arrive in Europe, sparking intense debate about borders and asylum. Across many countries, populist movements gained ground, often skeptical of the EU, of immigration, or of established political parties. The sharpest break came in the United Kingdom. In a 2016 referendum, British voters narrowly chose to leave the EU, a decision nicknamed Brexit, and the UK formally left in 2020, the first country ever to do so. More recently, energy has become a pressing worry, as Europe has tried to reduce its dependence on Russian oil and gas.

Russia's resurgence and the war in Ukraine

After the Soviet collapse, Russia went through a chaotic and painful decade. In 1999 to 2000 a former intelligence officer, Vladimir Putin, came to power, and over the following years he restored a strong, centralized state and sought to reassert Russia's standing as a great power. Many in Russia welcomed the renewed stability and pride, while critics pointed to shrinking political freedom, controlled media, and the harsh treatment of opponents.

Russia's relations with its neighbors and the West deteriorated. In 2014, after Ukraine's pro-Russian president was ousted in a popular uprising, Russia seized and annexed Crimea, a part of Ukraine, and backed armed separatists in eastern Ukraine. Most of the international community refused to recognize the annexation as legal.

Then, in February 2022, Russia launched a full-scale invasion of Ukraine. This was the largest war in Europe since 1945. The Russian government offered several justifications, claiming it needed to protect Russian speakers, to "de-militarize" Ukraine, and to stop NATO from expanding toward its borders. These stated reasons should be reported, but they have been widely rejected and do not justify the attack: Ukraine is an independent country, and crossing its borders by force to seize territory is, under the rules most nations accept, an act of aggression. Much of the world condemned the invasion, many countries imposed heavy economic sanctions on Russia, and Western nations sent large amounts of aid and weapons to help Ukraine defend itself. The war has caused enormous loss of life and destruction and, as this is written, continues.

One clear effect has been to give NATO new purpose. An alliance that some had called outdated after the Cold War suddenly looked vital again to its members. Two countries that had stayed neutral for decades, Finland and Sweden, decided that neutrality no longer felt safe and applied to join NATO, with Finland joining in 2023 and Sweden in 2024. In trying to push the alliance back, Russia had instead caused it to grow and to draw closer together.

Why this story still matters

The Cold War and the building of the European Union shaped the Europe we see today. The line between East and West is gone, but its memory still influences politics, security, and how countries view Russia and one another. The EU remains one of the most ambitious peace projects in history, an attempt to make old enemies into partners, even as it argues about its own future. And the return of major war to the continent in 2022 has reminded Europeans that the peace they built cannot be taken for granted. To understand any single European country today, it helps to know which side of this divide it stood on, how it joined or did not join the European project, and how it remembers the long, tense, and ultimately transformed twentieth century.

We begin our tour of individual countries with one that sat firmly in the Western camp, helped found NATO, joined the European project and then left it, and has a long and influential history of its own: The United Kingdom (The United Kingdom). 👉