On September 10, 2025, NATO fighter jets successfully shot down multiple Russian drones that had entered Polish airspace, raising significant concerns about the escalating Russia-Ukraine war. This incident marks the first occurrence of unmanned Russian aircraft breaching the territory of a NATO member since the onset of the invasion of Ukraine in February 2022. While Moscow asserted that it did not intentionally target Poland, many European leaders expressed skepticism, suggesting that the drone incursions were deliberate.
In a notable response, Poland invoked Article 4 of the NATO treaty, a provision that allows any member state feeling threatened to request consultations within the North Atlantic Council (NAC). This council serves as the primary political decision-making body for NATO. Although NAC meetings are commonplace, invoking Article 4 paves the way for a special assembly to deliberate on the necessary actions the alliance should undertake. While this step is significant, it does not carry the same weight as invoking Article 5.
Article 4 permits any NATO member to call for a meeting of the NAC when they perceive a security threat. A typical NAC meeting occurs weekly at the ambassadorial level in Brussels, while summits feature heads of state. In contrast, Article 5 is the cornerstone of NATO, stipulating that an attack on one member is deemed an attack on all, thus necessitating a collective response from all 32 NATO members. This article was established in April 1949 to safeguard Western European nations against potential threats, particularly from the Soviet Union.
It is essential to note that Article 5 does not automatically activate upon an attack; the assaulted member must request its invocation. In this case, Poland would need to determine whether the Russian actions were intentional.
When Article 4 is invoked, it compels all NATO members, including the United States, to engage in discussions at the NAC. This could lead to a joint declaration or an action plan. On the other hand, invoking Article 5 carries weighty implications, as it obligates the U.S. to assist any European ally or Canada under attack. However, the response is not strictly defined, allowing each ally to determine its course of action. The U.S. president would need to consider Congressional perspectives when deciding on military action, yet military response is not a prerequisite of Article 5.
Throughout NATO's history, Article 4 has been invoked several times, including by Turkey in response to cross-border terrorism linked to the Syrian War and by eight NATO members following Russia's invasion of Ukraine on February 24, 2022. Conversely, Article 5 has only been triggered once since NATO's inception—on September 12, 2001, after the 9/11 attacks, prompting European allies to support the U.S. by deploying aircraft in American airspace.
By invoking Article 4, Poland aims to communicate its perceived security threat to all NATO allies, thereby highlighting the frequency of Russian airspace violations along the eastern frontier, particularly in northeastern Europe. While some of these incursions may be attributed to pilot error, the increasing regularity suggests a more deliberate approach by Russia to intimidate smaller NATO members and test Western defenses. Poland's initiative seeks to secure unwavering support from its allies in addressing these violations, as demonstrated by the recent coordinated action with the Netherlands in neutralizing the Russian drones.
The United States is expected to robustly support Poland's self-defense efforts following this significant breach of its airspace. Recent diplomatic engagements between Polish President Karol Nawrocki and U.S. President Donald Trump have reaffirmed the U.S. commitment to Poland, both politically and militarily. There is potential for the deployment of U.S. air defense systems, such as Patriot batteries, stationed in Germany, to bolster Poland’s defenses, although it remains unclear whether such a request has been formally made.
