It is the 31st country to join the Alliance. Finland officially became a member of NATO on Tuesday, April 4. Membership documents were handed over to the head of American diplomacy, Antony Blinken, whose country is the depositary of the founding treaty. “We declare Finland the 31st member of the Alliance with the receipt of these documents,” he immediately said during a ceremony at NATO headquarters in Brussels.

“It is of course a great day for Finland […] It is also a good thing for NATO,” Finnish Defense Minister Antti Kaikkonen said ahead of the ceremony. “I’m tempted to say that maybe that’s the only thing we can thank (Russian President Vladimir) Putin for, because he once again precipitated something that he said he wanted to avoid by attacking” Ukraine, commented Antony Blinken.

“Finland is now safe,” said Jens Stoltenberg. “Together, NATO allies represent 50% of the world’s military power. So as long as we stick together and protect each other and do so credibly, there will be no military attack on a NATO ally,” he explained.

The invasion of Ukraine by Russia upset security in Europe and reshuffled the cards, pushing Finland and Sweden to want to join the protective umbrella of NATO. By joining NATO, Finland, which was invaded by the Soviet Union in 1939, doubles the length of the border with Russia of the US-led alliance. She gains the protection of Section 5, the Collective Defense Pledge that an attack on one member “shall be considered an attack on all members.”

Objections from Turkey and Hungary have delayed Helsinki’s membership for months, and are still blocking Stockholm’s. “I am absolutely confident that Sweden will also become a member. It is, for NATO, for me, a priority to ensure that this will happen as quickly as possible”, assured Jens Stoltenberg.

In the process, British Prime Minister Rishi Sunak welcomed Finland’s “historic” membership in NATO and called on “all members” of the Alliance to approve that of Sweden, currently blocked by Turkey and Hungary. “All NATO members must now take the necessary decisions to admit Sweden as well, so that we can form a united Alliance to defend freedom in Europe and around the world,” Rishi Sunak said in a statement.