Founded in 1949, the North Atlantic Treaty Organization (NATO) has stood for decades as the world’s foremost military alliance. Initially comprising the United States, Canada, and ten European countries, NATO connects the United States with many of its closest allies. It has thus long been a critical instrument of U.S. foreign policy.
NATO was established as the Cold War set in between the Soviet Union and the U.S.-led West. The alliance embodied the concept of collective defense: its members pledged to defend one another from security threats. In particular, given the outsize strength of the U.S. military, NATO membership obligated the United States to defend its European allies from possible Soviet attack. In an extreme case, this defense could include the United States’ using its nuclear weapons, placing the NATO allies under what is called the U.S. nuclear umbrella.
The Soviet Union never attacked a NATO state. It collapsed in 1991, breaking into an array of weak countries in deep economic distress. Even the strongest of them, Russia, posed little threat to the West. But as the Soviet threat dissipated, so did NATO’s original reason for being. NATO leaders had to decide whether the alliance should survive—and if so, how its purpose and activities should evolve in this new era. One critical question, if NATO continued, was about enlargement: whether, when, and how it should admit new countries from Central and Eastern Europe.
This question sparked intense debate in the U.S. government and beyond. Shortly after President Bill Clinton took office in January 1993, the idea arose for what would become the Partnership for Peace (PfP), a forum for military cooperation between the alliance and countries from the former Soviet Union and Warsaw Pact. This idea gained support among U.S. officials, though they disagreed over whether to go further and outline a clear path for new countries to formally join the alliance in the foreseeable future. At stake was the future of a continent that had been plagued for eighty years by two world wars and a cold war.