Poland has invoked Article 4 of the North Atlantic Treaty Organization after shooting down Russian drones that entered its airspace on Wednesday. 

The incident came three days after Russia’s largest aerial attack on Ukraine since the start of its current invasion in 2022, and represents the first time a NATO member is known to have fired shots since that war began. 

The article is not as well known as the treaty’s Article 5, which stipulates that an attack on one of the military alliance’s 32 member states is considered an attack on all. 

But it is increasingly being invoked. 

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.”

Essentially, it meant that Poland could demand to consult with its fellow NATO members.

NATO allies swiftly hold talks

As a result, NATO allies swiftly held talks Wednesday on the incursion by multiple Russian drones into Polish — and therefore 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 NATO.

But Polish Prime Minister Donald Tusk told Parliament that the discussions were held under Article 4 of the treaty, which founded NATO in 1949 in the aftermath of the Second World War.

Bob Deen, an analyst at the Clingendael think-tank in The Hague, said the article is “designed to promote better co-ordination 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.”

It’s not the first time Poland has invoked Article 4 in recent years. It previously did so early in Russia’s war on Ukraine.

WATCH | Here’s what you need to know about NATO’s Article 4: 

Poland has invoked Article 4 of NATO’s treaty after Russian drones. What does that mean?

At least three Russian drones have been shot down by Poland after violating its airspace on Wednesday. Prime Minister Donald Tusk said he has activated Article 4 of NATO’s alliance in response. As Russian military expert Keir Giles explains, this is different from Article 5 of the treaty, which says that an attack on one NATO member is an attack on all.

Warsaw joined Bulgaria, Czechia, Estonia, Latvia, Lithuania, Romania and Slovakia in requesting consultations on Feb. 24, 2022, following Russia’s full-scale invasion of the neighbouring Ukraine.

Article 4 doesn’t necessarily lead to Article 5

Article 4 consultations do not automatically lead to action under NATO’s Article 5. 

Poland first invoked Article 4 on March 3, 2014, “following increasing tensions in neighbouring Ukraine, as a result of Russia’s aggressive actions,” according to the NATO website. 

“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.

The article doesn’t necessarily lead to military action or a step toward Article 5, though both articles are related. 

“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,” Deen said.