After the Soviet Union’s collapse in 1991, the alliance took on a wider role. NATO forces — made up of troops volunteered by member states — operated as peacekeepers in Bosnia in the 1990s and bombed Serbia in 1999 to protect Kosovo, where the alliance still has troops.
Which countries are members?
In addition to the United States and Canada, the countries that became part of NATO in 1949 were Belgium, Britain, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway and Portugal.
Since then, 20 more European states have joined: Albania, Bulgaria, Croatia, the Czech Republic, Estonia, Finland, Germany, Greece, Hungary, Latvia, Lithuania, Montenegro, North Macedonia, Poland, Turkey, Romania, Slovakia, Slovenia, Spain and Sweden.
Finland became a member in 2023 and Sweden joined in 2024, abandoning their military nonalignment in the wake of Russia’s invasion of Ukraine. Finland shares an 830-mile border with Russia.
Membership in NATO has long offered protection under the American nuclear umbrella and the principle of collective defense. But the alliance also has extensive requirements — not just spending goals for the military, but specific demands for capabilities, armaments, troop strengths and infrastructure.
