Which country became NATO's 32nd member that day?

Sweden had avoided formal military alliances for roughly two centuries, a policy rooted in its 19th-century decision to stay out of European power politics. Russia's 2022 invasion of Ukraine changed the calculus for previously non-aligned northern European states, and Sweden completed the process of joining NATO, becoming its 32nd member on March 7, 2024, and gaining the alliance's mutual-defense guarantees.

Finland is a natural mix-up because the two Nordic neighbors originally applied together and share a similar history of non-alignment, but Finland actually completed its accession about a year earlier, since Turkey and Hungary delayed ratifying Sweden's membership. Austria, meanwhile, remains one of Europe's few officially neutral states and did not join NATO at all.

Finland's accession the year before had already roughly doubled NATO's land border with Russia, since Finland shares a long border that Sweden does not. Sweden's own accession instead closed the ring around the Baltic Sea, since with both Nordic countries now members, nearly every country bordering that sea belongs to NATO.