“Ukraine is under heavy attacks, like daily, 24/7,” Estonian Foreign Minister Margus Tsahkna told reporters, appealing for more military materiel for Ukraine like air defence systems, drones and artillery shells.

“We need to give these systems which we are not using to Ukraine, to take and protect their people, civil infrastructure and also energy infrastructure,” he said, before a ceremony with his counterparts to mark the day Nato’s founding treaty was signed: April 4, 1949, in Washington.

A bigger celebration is planned when Nato leaders meet in Washington from July 9 to 11.

At a small ceremony outside Brussels on Wednesday evening, US Secretary of State Antony Blinken paid tribute “to the millions of soldiers, sailors, and aviators whose courage and willingness to put their lives on the line have given weight to our sacred commitment to defend one another”.

Blinken said that even as foreign ministers mark more than seven decades of peace, “that security – together with the Alliance’s core principles of democracy, liberty, and the rule of law – is once again being threatened by those who believe that might makes right … and who seek to redraw borders by force.”

Sweden’s foreign minister, Tobias Billstrom, is taking part in the first ministerial-level meeting since his country became Nato’s 32nd ally last month. Russia’s full-scale invasion of Ukraine in February 2022 drove Sweden and Finland into Nato’s arms.

The alliance’s ranks have almost tripled from its 12 founding members, but Finland and Sweden joined in record time to shelter under Nato’s collective security guarantee, after coming under pressure for compensation from populist leaders in Turkey and Hungary.

That promise – Article 5 of the Washington Treaty, which has been shipped to Brussels for the ceremony – stipulates that an attack on any one of their number must be met with a united response. It’s only ever been used once, after the al-Qaeda attacks on US soil in 2001.

“Nato was founded on a single, solemn promise: an attack on one ally is an attack on all,” Nato Secretary General Jens Stoltenberg said on the eve of the anniversary. “From that foundation, we have built the most powerful and successful alliance in history.”

Among the more recent successes as it grew from the Cold War and after the Berlin Wall collapsed, Nato would count its 1999 air campaign against former Yugoslavia to end a bloody crackdown on separatist ethnic Albanians and its effort to avert near civil war in Macedonia in 2001.

At the other end of the scale lies the operation in Afghanistan. Nato took command of the security effort in 2003, and it became the longest, costliest and deadliest in alliance history. It was marked by a chaotic retreat in August 2021, many of the successes over almost two decades abandoned.

Today, Ukraine also wants a seat at Nato’s table, but the alliance works on unanimity and there is no consensus on whether it should join. Most allies oppose membership while war rages on anyway. For now, Nato promises only that its door is open for Ukraine in the future.

Russia’s President Vladimir Putin said he launched the war, in part at least, because Nato was expanding closer to Russia’s borders.

Nato allies cannot agree on whether to arm Ukraine either. As an organisation, the alliance only provides non-lethal support like transport vehicles, fuel, combat rations, medical supplies and demining equipment. However, many members provide arms and ammunition bilaterally or in groups.

The bulk of Nato’s efforts since Russian troops began massing for the invasion has focused on reinforcing its own borders near Russia and Ukraine to dissuade Putin from targeting any of the allies next.

On Wednesday, Russia said that Nato had returned to a Cold War mindset. Foreign Ministry spokeswoman Maria Zakharova told reporters Nato had no place in the “multipolar world” Moscow says it seeks to build to end US dominance.

Additional reporting by Reuters and Agence France-Presse