NATO allies swiftly held talks Wednesday on the incursion by multiple Russian drones into Polish — and alliance — airspace and the shooting down of some of the weapons by Polish and Dutch fighter jets.

The consultations at NATO headquarters were part of a regular meeting of ambassadors from the alliance’s 32 member states known as the North Atlantic Council, but Polish Prime Minister Donald Tusk told Parliament that they came under Article 4 of the treaty that founded NATO in 1949 in the aftermath of World War II.

The incident in Poland came three days after Russia’s largest aerial attack on Ukraine since the war began.

Article 4 can put urgent matters on the agenda

Article 4, the shortest of the NATO treaty’s 14 articles, states that: “The Parties will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened.”

Bob Deen, an analyst at the Clingendael think tank in The Hague, said the article is “designed to promote better coordination and understanding within the alliance on external threats. It gives all allies the opportunity to urgently put certain threats or developments on the agenda of the North Atlantic Council.”

Article 4 is increasingly invoked

Poland previously requested such consultations early in Russia’s war on Ukraine. They do not automatically lead to any action under Article 5 of the treaty, which is NATO’s collective security guarantee, with allies pledging that an attack on one member of the alliance constitutes an attack on all.

“Article 4 gets invoked relatively rarely but increasingly in recent years; Turkey alone invoked it five times between 2003-2020 in the context of Syria and Iraq,” said Deen in emailed comments in response to questions from The Associated Press. “Eight allies invoked it in 2022 shortly after Russia’s full-scale invasion of Ukraine and Poland has triggered it once in 2014 ... after Russia’s illegal annexation of Crimea.”

Poland first invoked Article 4 on March 3, 2014, “following increasing tensions in neighboring Ukraine, as a result of Russia’s aggressive actions,” according to the NATO website. And Warsaw joined Bulgaria, Czechia, Estonia, Latvia, Lithuania, Romania and Slovakia in requesting consultations on Feb. 24, 2022, following Russia’s full-scale invasion of Ukraine.

This doesn’t necessarily mean a step toward Article 5

Deen said that Article 4 is related to Article 5, but is “not necessarily a ‘stepping stone.’”

“Article 5 has only been invoked once, in response to the 9/11 attacks on the United States, immediately bypassing article 4. In other words: Article 4 can be invoked without triggering Article 5, and vice versa,” he said.