NATO Enlargement (NSC)

What Actually Happened

On January 10, 1994, President Bill Clinton made a speech at a North Atlantic Council summit in Brussels, Belgium. He announced the creation of the Partnership for Peace, based on military cooperation, defense reform, and information-sharing, between European members and nonmembers of the North Atlantic Treaty Organization (NATO). The partnership, conceptualized by U.S. military officials, was envisaged as a way to increase cooperation between former Soviet states and NATO.

More important, Clinton said the partnership would set in motion “a process that leads to the enlargement of NATO.” At a speech in Prague two days later, Clinton went further, saying that “the question is no longer whether NATO will take on new members but when and how.” With these statements, he affirmed that NATO would extend membership to former Eastern Bloc states, settling a question that had preoccupied NATO and U.S. officials since the collapse of the Soviet Union. Unlike the Warsaw Pact, which had been dissolved in 1991, NATO would carve a place for itself in post–Cold War Europe.

Yet the pace of enlargement was slow. The Clinton administration thought that moving too quickly would jeopardize the development of a cooperative relationship with Moscow and undercut U.S. support for reform in Russia. This in mind, Clinton avoided announcing an explicit timeline and plan for enlargement. In May 1997, NATO and Russian leaders met in Paris to sign the Founding Act on Mutual Relations, Cooperation, and Security, which was meant to serve as a road map for future NATO-Russia cooperation. Under the agreement, which noted that the two parties did “not consider each other as adversaries,” the parties agreed to establish a joint council “to build increasing levels of trust, unity of purpose, and habits of consultation and cooperation between NATO and Russia.”

In July 1997, three years after Clinton’s landmark speech in Brussels, NATO formally invited the Czech Republic, Hungary, and Poland to join the alliance. Almost two years later, after the accession of the three countries was ratified by each NATO member’s parliament, the countries formally became members of NATO. On March 16, 1999, their flags were raised at the NATO headquarters in Brussels. 

How was the decision made? 

Many important figures in the Clinton administration pushed for enlargement. The strongest support came from National Security Advisor Anthony Lake and U.S. Ambassador to the United Nations Madeleine Albright, who would become Secretary of State in 1997. They believed that enlargement was necessary to provide stability to Europe and ensure the consolidation of democracy and free market economies in Eastern Europe. The outbreak of ethnic conflict in the Balkans following the collapse of the Soviet Union also gave enlargement a sense of urgency: many policymakers felt the need to fill the security vacuum in Eastern Europe and prevent any backsliding to authoritarianism or animosity towards the West. 

Outside the halls of the West Wing, both domestic and international actors supported enlargement. Domestic public opinion of enlargement was strongly favorable, particularly in critical electoral districts in the midwest. There, large numbers of Americans of Eastern European descent, particularly from Poland, supported NATO enlargement The European member states of NATO, particularly Germany, were also strong proponents of enlargement, which they saw as a way to push NATO’s eastern border—and thus their buffer against invasion—further east. 

Skepticism about enlargement mainly came from U.S. military leaders, who did not want to overcommit U.S. military resources to the defense of Central and Eastern Europe out of concern that it would dilute NATO’s effectiveness. Other critics, including former diplomats such as George Kennan, argued against enlargement for other reasons, including that it would jeopardize the West’s relations with Russia. Their arguments, however, were ultimately outweighed by the overwhelming support for enlargement elsewhere in the government. 

What did the decision mean? 

The decision to enlarge NATO sent ripples through domestic and international politics. In particular, NATO enlargement has had the most effect in three crucial areas: NATO membership, its strategic orientation, and its relations with Russia.

1. NATO Membership 

The accession of the Czech Republic, Hungary, and Poland to NATO heralded a number of future expansion rounds. Shortly after they joined the alliance, a Membership Action Plan (MAP) was created, which provided a structured approach and specific guidelines for new countries wishing to join the alliance. 

In 2004 seven new countries, including the three Baltic states, joined NATO, marking the first accession to NATO by former Soviet Republics. A third round of expansion added two new countries, Albania and Croatia, in 2009. Montenegro joined in 2017 and North Macedonia in 2020.  In the wake of Russia’s 2022 invasion of Ukraine, Finland and Sweden joined. Today, NATO has thirty-two members, covering almost one billion citizens. It has recognized three aspiring countries—Bosnia and Herzegovina, Georgia, and Ukraine—that are currently pursuing membership. 

2. NATO’s Strategic Orientation

The decision to enlarge NATO after the disintegration of the Soviet threat was a harbinger of a new strategic orientation for the alliance. In a continuation of its dual-track policy, launched in the 1960s, NATO refocused its mission and expanded its political aims to ensuring European cooperation and democratic stability in its member states. Hans Jochen Peters, a German diplomat, argues that enlargement was a crucial component of this reorientation, by signaling that NATO was “adapting . . . to the new international strategic environment.” 

3. NATO-Russia Relations 

In the two decades following NATO's decision to expand membership, Russia’s relations with the West have been marked by disagreement, tension, and mistrust. But scholars hotly debate whether NATO enlargement caused this deterioration in relations—and if so, to what extent. 

Some scholars argue that upon enlarging NATO, the alliance isolated Russia from the rest of Europe, framing the country as an outsider and adversary. George Kennan, author of the famous “X Article,” famously called NATO enlargement policy “the beginning of a new cold war.” Vladimir Putin has called NATO enlargement a “direct threat” to Russia’s security and has often used it to partially justify Russia’s aggressive foreign policy. Putin’s strategy has been very effective, argues Charles Kupchan: “Putin essentially creates a political legitimacy that is grounded on standing up to the West.”

On the other hand, some scholars argue that it was not NATO enlargement itself that damaged U.S.-Russia relations but something else along the way. Celeste Wallander, president of the U.S. Russia Foundation, argues that the state of the relationship is due to “the Russian leadership, under Putin, [rejecting] the entire project of integration, of globalization, of transparency.” Proponents of this viewpoint emphasize the 1997 NATO-Russia Founding Act, in which both parties declared their commitment to a non-adversarial relationship, and the subsequent periods of relative cooperation that occurred before the 2008 Russian intervention in Georgia. (Russian leaders argue that NATO violated the Founding Act when it deployed troops to Central and Eastern Europe in 2016.) 

Was it a good idea? 

Even less agreement exists on whether NATO enlargement was the correct policy decision. Some think it was the right decision; others think it was the right decision but executed incorrectly; yet others think it was a disastrous mistake. 

The late Ronald D. Asmus, who had served as deputy assistant secretary of state for European affairs, contended that NATO enlargement achieved its goals of stabilizing Europe and even argued that it was “partially successful in dealing with Russia.” Kupchan, conversely, argues that in the end the costs of enlargement far outweighed the benefits, ultimately jeopardizing Russia’s relationship with the West. Somewhere in the middle, Wallander claims that while NATO enlargement achieved its objectives of stabilization and democratization, a strategic mistake was made in discounting how Russia would react to the policy. 

Ultimately, the decision to expand NATO membership resists a clear-cut assessment. Whether NATO enlargement was the right choice—whether it irrevocably damaged the West’s relations with Russia or stabilized the European security environment or achieved something in between—it will fall to future generations to navigate NATO-Russia relations and set the course for NATO’s future.