(Brussels) After three decades of military non-alignment and in the midst of war in Ukraine, Finland became the 31st member of NATO on Tuesday, a “historic day” hailed by the leaders of the Alliance which now looks to Sweden.

In a strong signal sent to Russia, which denounced an “attack” on its security and promised “countermeasures”, the NATO allies welcomed the Nordic country with great fanfare and immediately called for its membership. Swedish neighbor “as quickly as possible”.

US President Joe Biden said he was “proud” to welcome Helsinki to the Western military alliance.

“When (Vladimir) Putin launched his brutal war of aggression against the Ukrainian people, he thought he could divide Europe and NATO. He was wrong. Today, we are more united than ever,” he said in a statement.

His French counterpart Emmanuel Macron tweeted: “Welcome Finland to NATO! while Ukrainian President Volodymyr Zelensky offered his “sincere congratulations” as Kyiv also aspires to one day join the military organization.

As a depositary country of the North Atlantic Treaty, it was the head of American diplomacy Antony Blinken who formally announced Finland’s accession during a brief ceremony at NATO headquarters in Brussels.

He had previously been given the instruments of ratification of the Helsinki membership by Turkey, which has long blocked the entry of the Nordic country and which still opposes, as well as Hungary, that of Sweden.

“The era of military non-alignment in our history is coming to an end. A new era begins,” said Head of State Sauli Niinistö before the Finnish flag was raised at NATO headquarters between those of Estonia and France, following alphabetical order.

US Secretary of State and NATO Chief Jens Stoltenberg hailed a “historic day”.

“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.

The Nordic country which shares a 1300 kilometer long border with Russia became the 31st member of the Alliance on the anniversary of its creation, April 4, 1949.

“Finland is now safe,” said Jens Stoltenberg.

“Together, the 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.

By joining NATO, Finland, which was invaded by the Soviet Union in 1939, doubled the length of the border with Russia from the US-led Alliance.

She gets 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 delayed Helsinki’s membership for months and are still blocking Stockholm’s.

In unison, the leaders of the Alliance immediately called for Sweden to join them, from British Prime Minister Rishi Sunak to German Chancellor Olaf Scholz.

“We encourage Turkey and Hungary to ratify Sweden’s accession protocols without delay so that we can welcome Sweden into the Atlantic Alliance as soon as possible,” Blinken said.

“I call on (Turkish) President Erdogan not to ruin the Vilnius summit” in July, his Lithuanian counterpart Gabrielus Landbsergis said, saying he hopes to see “Sweden’s flag flying at the NATO”.

Chance of the alphabetical order, the colors of Sweden would then be hoisted between those of Spain and Turkey.

The accessions of the two Nordic countries are the demonstration that “the door of NATO remains open”, hammered Jens Stoltenberg. “NATO’s position remains unchanged: Ukraine will become a member of the Alliance,” he continued.

However, he added immediately, “the main objective at the moment is its survival as a sovereign and independent country, otherwise to speak of membership is meaningless”.

NATO foreign ministers are due to meet with their Ukrainian counterpart Dmytro Kuleba and will discuss “long-term support” in Kyiv.

“Ukraine is aiming for the same goal as Finland in becoming a full member of NATO, and our conversations here in Brussels will focus on how we can move forward,” the Ukrainian minister said upon arrival .

A meeting of the NATO-Ukraine Commission was organized for this purpose despite objections from Hungary.