Sweden officially joined the Western security alliance NATO on Thursday, ending decades of neutrality in Europe.
The nation’s inclusion means the alliance has expanded to 32 members, a significant rebuff to Russia, which has long tried to counter NATO’s influence.
For Stockholm, it also means facing a new and challenging security environment in Europe after pledging neutrality among the continent’s competing factions for 200 years.
NATO Secretary General Jens Stoltenberg said it was a “historic day.”
“Sweden will now take its rightful place at NATO’s table, with an equal say in shaping NATO policies and decisions,” Stoltenberg said in a statement. “Sweden brings with it capable armed forces and a first-class defence industry. Sweden’s accession makes NATO stronger, Sweden safer and the whole Alliance more secure.”
“Today’s accession demonstrates that NATO’s door remains open and that every nation has the right to choose its own path,” he added.
NATO will hold a ceremony Thursday to celebrate Sweden’s inclusion and will hoist the Swedish flag up along with the flags of the other 31 members of the alliance in Brussels, Belgium, and other alliance command centers in Europe and North America.
Swedish Prime Minister Ulf Kristersson said in a statement that NATO is “stronger together.”
“We will strive for unity, solidarity and burden-sharing,” he said, pledging to uphold the values of “freedom, democracy, individual liberty and the rule of law.”
Sweden applied to join NATO shortly after Russia invaded Ukraine in 2022. But while Finland was ratified relatively quickly into the alliance last year, Sweden faced a number of hurdles to gain admittance into NATO, which requires ratification from each member nation to include a new ally.
Turkey held up Sweden’s bid over concerns about Stockholm’s support for what it calls Kurdish terrorist groups, while Hungary hesitated over concerns about Swedish comments on Hungarian democracy. Both countries ultimately approved Sweden into the alliance this year after forging deals, including military aircraft sales.
President Biden said in a statement the inclusion of Sweden into NATO means the alliance is “stronger than ever,” which he called a victory against Russian President Vladimir Putin.
“When Putin launched his brutal war of aggression against the people of Ukraine, he thought he could weaken Europe and divide NATO,” Biden said, noting that instead the alliance has grown with the addition of Finland and Sweden. “Today, we once more reaffirm that our shared democratic values—and our willingness to stand up for them—is what makes NATO the greatest military alliance in the history of the world. It is what draws nations to our cause. It is what underpins our unity.”
Sweden will join the alliance amid a fractious time in Europe, with the war in Ukraine continuing to rage on, creating unease about the future of security on the continent.
But Swedish forces are expected to integrate smoothly into the alliance, with troops already participating in an ongoing NATO drill across Europe, the largest in decades.
Updated at 12:49 p.m.