Background

NATO’s Foundation

NATO arose from the political and economic shifts in Europe that followed World War II. Although the Soviet Union had been allied with the United States, France, and the United Kingdom during the war, postwar Europe fell into a stark division between a democratic West friendly to Washington and a communist East that looked to Moscow. The division solidified along ideological lines. Moscow’s assertion of control over Eastern Europe served its ambition to maintain a foothold in Europe and spread communism throughout the world. The Western ideals of free market capitalism and democracy opposed this, and U.S. and west European leaders feared the threat of communism to democracies in Europe and elsewhere. It became clear that the Soviet Union was no longer a partner, as it had been during the war. It was instead a rival.

As tensions between the Soviet Union and the West rose, west European countries became worried about their security. The United States was also prepared to sustain a long-term presence in Europe. These factors drove the United States, Canada, and ten west European countries to establish NATO. The alliance’s founding document, the North Atlantic Treaty, was signed in Washington, DC, on April 4, 1949. In Article 5 of the treaty, the allies “agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all.” Each also agreed to aid any other that was attacked. This notion of collective defense is the heart of the alliance. Because the United States was at the time the only nuclear-armed state among them, the allies came under the so-called U.S. nuclear umbrella. This security guarantee has always been a critical aspect of NATO’s strategic position. 

By its own account, NATO was formed for three purposes: to deter Soviet expansionism, to prevent violent nationalism from reemerging, and to encourage democratic norms and political cooperation in Europe. These purposes aligned with the views of U.S. and other NATO leaders that a continent of economically vibrant and militarily capable states, firmly linked with one another, could best resist communist expansion. NATO was also a vehicle to keep the United States committed to Europe’s security. NATO’s first secretary-general, Hastings Lionel Ismay of the United Kingdom, memorably put the alliance’s aims succinctly: to “keep the Soviet Union out, the Americans in, and the Germans down.” 

NATO During the Cold War

NATO quickly began to fulfill its mission as both a military alliance and a political anchor of the U.S.-led Western order. One early area of activity was enlargement. Greece and Turkey joined in 1952, followed by what was then West Germany in 1955. 

Eight days after West Germany’s entrance, the Soviet Union and seven of its east European satellite states established the Warsaw Treaty Organization, an alliance better known as the Warsaw Pact. Soviet leaders intended the pact to be a counterweight to NATO and to strengthen Soviet control over the region. Like NATO, the Warsaw Pact was a nuclear alliance; the Soviet Union had tested its first nuclear weapon in 1949. 

Given that any conflict between the Soviet Union and the West could escalate to nuclear war, military doctrine focused heavily on deterrence—the idea of preventing an attack by threatening retaliation. This approach was underscored by the concept of mutually assured destruction, premised on the idea that the United States and the Soviet Union each had nuclear arsenals large and reliable enough to destroy the other.

Throughout the Cold War, NATO retained an important political role. The 1967 NATO report “The Future Tasks of the Alliance” introduced a dual-track policy: the idea of both maintaining adequate defense and promoting political cooperation and dialogue. This line of thinking—broadening the organization’s goals and approach to security—had a lasting effect on NATO’s strategic vision. The report laid the foundation for the negotiation of the Helsinki Final Act, which offered inspiration and a legal foundation for later efforts to bring democracy and human rights to Soviet-dominated Eastern Europe. Meanwhile, NATO endured as a mechanism to support and maintain democracy in Europe. A newly democratic Spain joined the alliance in 1982, the first addition since West Germany. 

Conclusion of the Cold War

In the 1980s, the Soviet Union began to face growing economic strain and civil discontent. Soviet leader Mikhail Gorbachev responded with two initiatives: perestroika (restructuring) and glasnost (openness). Perestroika aimed to reform the Soviet economy and political system by, for example, giving local governments more power and reducing the state’s role in planning and directing companies’ actions. Glasnost eased the strict social controls that Moscow imposed on Soviet citizens. Even with these reforms, the Soviet Union was far from a free market democracy. It was, however, inching in this direction. 

These transitions took hold outside the Soviet Union as well, and communist rule began to crumble in Warsaw Pact countries. Civil society leaders throughout Eastern Europe had long campaigned, often under severe repression, to free their countries from Soviet domination. Gorbachev’s reforms in the Soviet Union emboldened these democratic movements. In the late 1980s, Gorbachev allowed them to break through. In a landmark speech at the United Nations in December 1988, he announced that the Soviet Union would reduce its military presence in Eastern Bloc countries. The following July, he said that he would no longer prop up their communist governments. In other words, the Soviet Union would not use repression and force to impose its will, as it had long done. This so-called Sinatra Doctrine signaled that democracy was coming.

By mid-1990, all the formerly communist states in Eastern Europe had undergone democratic transitions. One of the most dramatic moments came, fittingly, in divided Berlin. On November 9, 1989, the East German government’s spokesman announced, apparently unintentionally, that East German citizens could cross freely into the West. Within minutes, Berliners used hammers and picks to start bringing down the wall that had divided their city since 1961.

It took less than a year for Germany to be unified, West Germany absorbing East. Critically, the entire country then became a member of NATO. Taking in the former East German territory in October 1990 was the alliance’s first enlargement into the Eastern Bloc. Soviet leaders resisted this, pushing instead for Germany to have “associate membership” in both NATO and the Warsaw Pact. This initiative failed. Leaders did not view it at the time as the first step in a larger NATO expansion. Instead, they considered Germany a unique case. Either way, this event was a clear sign that NATO’s role in Europe was to endure.

The addition of a unified Germany to NATO was a harbinger of the collapse of the Warsaw Pact. Shortly after East Germany left the pact in preparation for its unification with the West, other countries, including newly democratic Poland, Czechoslovakia, and Hungary, began expressing a desire to withdraw from the organization and escape Soviet control. By July 1991, the Warsaw Pact had ceased to exist. 

The Soviet Union itself would not exist for much longer. In August 1991, hard-line communists seeking to regain control of the state attempted a coup d’état. Although unsuccessful, the event undermined Gorbachev’s power and strengthened the appeal of Boris Yeltsin, the leader of Russia’s democratic movement. Fall 1991 brought declarations of independence from numerous Soviet republics. On December 25, 1991, Gorbachev resigned as leader of the Soviet Union, which then dissolved into fifteen separate and struggling states. Yeltsin became president of the main one, formally called the Russian Federation and commonly known as Russia. 

In only a few years, Europe had undergone a radical transformation. The Soviet Union, the main adversary of the United States, had collapsed. Democratic governments were in power throughout Central and Eastern Europe.

Finally free to chart their own course, many newly independent east European countries were eager to cooperate with the West. NATO membership, and the security guarantee that came with it, seemed to be the perfect bulwark against any reassertion of Soviet dominance. In May 1990, President Vaclav Havel of Czechoslovakia had predicted that NATO could “become the seed of a new European security system.” Two years later, Havel, Polish President Lech Walesa, and Hungarian Prime Minister Jozsef Antall announced their intention to seek full membership in NATO.