Also under focus is Article 4, which allows member countries to bring up their own security concerns for formal discussion. Estonia and Poland invoked the article after multiple incursions by Russian drones and jets into NATO countries’ airspace.
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, 19 more European states have joined: Albania, Bulgaria, Croatia, the Czech Republic, Estonia, Finland, Germany, Greece, Hungary, Latvia, Lithuania, Montenegro, North Macedonia, Poland, Romania, Slovakia, Slovenia, Spain, Sweden and Turkey.
When Finland joined in 2023, in part a response to Russia’s Ukraine invasion, it extended the alliance’s commitment to collective defense to a country that shares an 830-mile border with Russia. Ukraine, which shares a nearly 1,300-mile internationally recognized border with Russia, has long aspired to NATO membership.
Sweden is the most recent signatory to the treaty, joining in 2024. It brought an advanced high-tech defense industry and enhanced NATO’s deterrence capabilities in the Baltic and North Seas.
