Last Friday, for the second time in less than two weeks and only the ninth time in history, Article 4 of the North Atlantic Treaty—NATO’s founding document—was invoked. While it was Poland that invoked the clause two weeks ago, this most recent invocation was by Estonia. Both instances came in response to deliberate incursions by Russian aircraft into the two countries’ airspace.
In the case of Poland, the incursion came in the form of 19 Russian drones that entered and remained in Polish airspace, before some were shot down by fighter aircraft from Poland and the Netherlands, a fellow NATO ally. In the case of Estonia, it was three Russian MiG-31 fighters that violated Estonian airspace over the Baltic Sea and remained in it for over 10 minutes. To put that latter incursion in context, in 2019, Turkey—another NATO ally—shot down a Russian fighter jet operating in Syria that had crossed into its airspace for less than 30 seconds. Hence, Russian aircraft flying over the territory of a small neighboring country for so much longer, at a time when NATO members consider the Russian invasion of Ukraine to be a direct threat to their security, is being rightfully viewed as provocative.
In addition to these two incidents, Russian drones crossed into Romania’s airspace last week, and this week, suspected Russian drones caused the shutdown of airports in Denmark, whose government is now also considering invoking Article 4.