NATO to hold Article 4 consultations as Estonia cites Russian airspace breach

NATO allies will hold formal consultations under Article 4 at Estonia’s request after Tallinn said three Russian fighter jets entered its airspace last week without authorization. Russia’s Defense Ministry denied the accusation. The intrusion lasted 12 minutes and came as the alliance reeled from broader signs of Moscow’s ongoing air-to-ground activity near Eastern Europe, including a separate incident involving drones in Polish airspace earlier this month.

Estonia prompted the talks by invoking Article 4, which calls on alliance members to consult when any member’s territorial integrity, political independence or security is threatened. The talks will be conducted by NATO’s 32 ambassadors in Brussels at the North Atlantic Council, a mechanism that emphasizes coordination and shared assessment rather than automatic policy steps. Article 4 is the shortest of the Washington Treaty’s 14 articles and does not itself obligate a military response, unlike Article 5, which commits members to collective defense if one is attacked. The decision to pursue consultations reflects the alliance’s preference for consensus-based, measured responses to perceived threats.

The timing follows a broader outburst of activity on Europe’s eastern flank. Earlier this month, Polish authorities said roughly 20 Russian drones penetrated Polish airspace on Sept. 10, prompting questions about air defense readiness and alliance coordination. In response, NATO launched Eastern Sentry, a temporary operation intended to bolster the alliance’s presence with European air forces and other defenses along its eastern flank two days after the drone incident. The move underscores the alliance’s effort to demonstrate readiness without escalating into a broader confrontation.

Poland itself has a long history with Article 4, having invoked it after Russia’s invasion of Ukraine in 2022. Before the drone episode, eight countries, including Bulgaria, the Czech Republic, Estonia, Latvia, Lithuania, Romania and Slovakia, had sought Article 4 consultations in response to the ongoing conflict in Ukraine. Poland first invoked Article 4 on March 3, 2014, amid tensions in neighboring Ukraine and Russia’s broader actions around Crimea. Analysts note that Article 4 is relatively rare, but its use has increased in recent years as threats on NATO’s eastern edge have heightened urgency for coordination. Turkey’s experience with invoking Article 4 multiple times between 2003 and 2020 in the context of Syria and Iraq is often cited to illustrate its non-automatic link to military action, according to defense analysts.

Bob Deen, an analyst at the Clingendael Institute in The Hague, said Article 4 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,” he told The Associated Press. Deen noted that Article 4 discussions can lead to joint decisions or actions, but they do not automatically trigger a response, unlike Article 5, which has only been invoked once—in the wake of the 9/11 attacks.

The sequence of events illustrates how NATO is trying to balance deterrence with diplomacy. Article 4 talks, while not guarantees of action, provide a framework for allies to express concerns, share intelligence, and align on potential defensive measures without precipitating a wider crisis. In the current cycle, Estonia’s request reflects concerns about Russia’s use of airspace and its broader approach to air defense and reconnaissance, while the alliance evaluates whether additional steps—such as enhanced air patrols or deployments along the eastern flank—are warranted in the near term.

The alliance has repeatedly emphasized that it remains prepared to respond to threats to any member’s security, but it has also stressed the value of measured, coordinated responses that avoid unnecessary escalation. As the consultations proceed, NATO will weigh the results of intelligence-sharing, assess the need for further exercises or deployments, and determine whether additional diplomatic or military steps are appropriate. In the meantime, the presence of Eastern Sentry, and the broader posture of increased air defense readiness, reflect NATO’s emphasis on deterrence through visible capability and alliance unity on eastern safeguards.