NATO marked Sweden's entry into the alliance on Monday with a flag-raising ceremony on a cold and rainy morning in Brussels.
"Sweden has taken its rightful place at NATO's table," Secretary General Jens Stoltenberg said at alliance headquarters, speaking alongside Swedish Prime Minister Ulf Kristersson.
Sweden's accession expands the Western defence alliance to 32 members, and the country is now protected by NATO's powerful collective defence pact, article 5, after breaking from a 200-year tradition of non-alignment.
Finland and Sweden both asked to join the alliance in May 2022, following Russian President Vladimir Putin's full-scale invasion of Ukraine in February of that year.
Finland managed to join NATO ahead of Sweden after Turkey, and later Hungary, opposed Stockholm's entry. Ankara pursued and received greater commitments from Sweden to combat terrorism.
All NATO members have to formally approve new members. Budapest never spelled out a specific objection to Swedish membership and promised Hungary would not be the last country to ratify, although it did turn out this way.
Russia warned Finland and Sweden against joining the alliance with ambiguous threats of a retaliation, however Kristersson detailed no major concern.
"We should not be naive. And I think we are more aware of the risks that they pose to us now than we have ever been before," he said. "So simply still stay alert," Kristersson added.