Why NATO Article 4, which Poland is appealing to after the Russian drone attack, is key

All NATO partners are participating in an urgent consultation on how to react.

Article 4 of the North Atlantic Treaty , also known as the Washington Treaty, determines how the parties are to act when, in their judgment, "the territorial integrity, political independence, or security" of any of the alliance members is threatened. In all these cases, the partners may open a period of consultation.

It's important to be clear that this is a deliberative mechanism in crisis situations, such as the one experienced by Poland this Wednesday, when Russian drones entered its airspace . They were shot down with the collaboration of NATO military assets.

Article 4 in no way implies the initiation of joint military action. This is precisely what the following article, number 5, regulates.

For this reason, invoking Article 4 does not entail an obligation to intervene militarily, but it may lead to the activation of preventive or deterrent measures, such as the deployment of additional armed forces on the territory or the strengthening of specific areas of the defense mechanisms.

This is not the first time Warsaw has invoked Article 4. It did so jointly with the three Baltic republics - Estonia, Latvia, and Lithuania - in 2014 and 2022. Eleven years ago, they resorted to this mechanism coinciding with the invasion of the Crimean Peninsula, which Moscow unilaterally annexed. In early 2022, they did so again, once Moscow began its military offensive in the rest of Ukraine .

Turkey has also invoked Article 4 on several occasions. The first time was in 2003, just before the US-led invasion of Iraq began. It was a war that tore NATO partners in two. Ankara subsequently invoked it again in several episodes linked to the long war that raged in neighboring Syria between 2011 and last year.

The big news this Wednesday is that this is not a preemptive action, but rather an attempt to assess how to respond to an operation that Poland described as a "likely large-scale provocation."

The North Atlantic Treaty has thirteen additional articles, as well as a preamble, which establish the foundations of the common defense system.

Number five establishes that any "armed attack" on any of the countries comprising the alliance will be considered an aggression "against all parties" and, consequently, they may adopt "the measures they deem necessary, including the use of armed force." The objective is to "restore security."

Article 6 then details what constitutes an armed attack. At the territorial level, it covers Europe, North America, Turkey, or the islands north of the Tropic of Cancer that are under the jurisdiction of any state. The treaty was signed in 1949, before the decolonization of Algeria, so it includes a specific mention of this country, which was then considered a department of France.

The Washington Treaty is the backbone of a system that requires all parties to intervene in the event of aggression against one of their allies. It was first invoked during the 2001 US jihadist attacks.