BRUSSELS, July 11 — The enlargement of NATO has reshaped the European security map in ways that were barely conceivable five years ago, and the mechanics here are worth dissecting. Finland and Sweden, two nations with long histories of military non-alignment, applied for membership within months of Russia’s full-scale invasion of Ukraine on February 24, 2022. Finland joined on April 4, 2023, adding a 1,340-kilometer border with Russia.
Sweden became the 32nd member on March 7, 2024, after Turkey and Hungary ratified its accession. The catch in this expansion story is that the alliance’s own strategic posture had already shifted before the applications landed.
At the Madrid summit in June 2022, NATO adopted a new Strategic Concept that identifies Russia as “the most significant and direct threat” to its members. That language is not boilerplate; it drives resource allocation and troop deployments. The eastern flank has been reinforced with additional troops and equipment, including a multinational battlegroup in Romania.
Follow the money
Defense spending among NATO members has climbed sharply. In 2021, only six of the then-30 members met the alliance’s target of spending 2% of GDP on defense. By 2024, that number had risen to 23 out of 32 members.
The trend is clear: the invasion of Ukraine concentrated minds in capitals that had long treated the 2% target as aspirational rather than binding. On closer reading, the spending increases are not uniform — some members have surged past the target while others remain below — but the direction of travel is unmistakable.
The alliance now stretches from the Arctic to the Black Sea, with Finland’s border adding a direct land frontier between NATO and Russia that did not exist before. That border runs through forests and lakes in the Nordic region, and its military implications are significant: NATO forces can now operate on Russia’s northwestern flank, and Russia must allocate resources to monitor a much longer border.
Ukraine is not a member
Ukraine remains outside the alliance, despite its application for membership and the ongoing war. Instead, it receives extensive support through the Ukraine Defense Contact Group, a coordination mechanism formed in April 2022 that brings together dozens of countries to supply weapons, training, and equipment. The group is not a NATO structure but operates alongside it, and its existence reflects the alliance’s careful calibration: support Ukraine heavily, but do not trigger Article 5 by admitting a country already at war.
The question going forward is whether the enlargement process has reached a natural pause or whether further expansion is on the table. The 2022 Strategic Concept is clear on Russia, but the alliance has not formally extended an invitation to any other aspiring member since Sweden’s accession.
The mechanics of further enlargement would require unanimous consent from all 32 members, a high bar in the current political environment.
