Finland and Sweden formally ask to join NATO, in potentially its biggest expansion in two decades

Finland and Sweden formally submitted their bids for NATO membership on Wednesday morning, casting aside decades of strategic neutrality to embrace the military alliance in a stunningly swift transformation prompted by Russia’s invasion of Ukraine.

Finnish and Swedish envoys delivered letters expressing their nations’ interest in joining NATO to Secretary General Jens Stoltenberg at the alliance’s headquarters in Brussels. Stoltenberg has said that NATO would seek to admit both nations in a fast-track process.

The two Nordic states, which have had close relations with NATO but long remained militarily nonaligned, have seen public opinion tilt heavily in favor of joining the alliance since Russia’s invasion of Ukraine upended European security. If both are admitted, it would mark NATO’s most significant expansion in nearly two decades, increasing the organization’s membership to 32 nations and adding hundreds of additional miles of border with Russia.