Wednesday morning's incursion of Russian drones into Polish airspace led to jets being scrambled, an emergency government meeting being called - and concerns that Europe and NATO's resolve against Moscow may not be up to the test.

Poland's Prime Minister Donald Tusk said Polish airspace was violated 19 times and at least three drones were shot down by Warsaw's jets, aided by Dutch F-35s and an Italian early warning aircraft. Russia has pushed back against accusations that the incursion was deliberate – though it also stopped short of denying its drones had trespassed sovereign Polish airspace. No objects on Polish territory were planned to be targeted, Moscow said.

But European officials have forcefully batted off suggestions the act may have been unintentional. There is no evidence whatsoever that this amount of drones flew over this route over... Polish territory by accident, Germany's Defence Minister Boris Pistorius said, while his Italian counterpart Guido Crosetto called the overnight events in Poland a deliberate attack with the double aim of provoking and testing.

Although Poland has experienced several violations of its airspace since neighbouring Ukraine was attacked by Russia in February 2022, this latest incursion - sizeable, and deep into Polish territory - sparked real nervousness in Warsaw. Tusk warned that Poland was at its closest to open conflict since World War Two. He also requested invoking Article 4 of the NATO treaty, which allows member countries to start a discussion with allies about threats to their security.

Some experts believe the drones – some of which flew towards Rzeszow airport, a major logistical hub for defense supplies and humanitarian aid bound for Ukraine – may have had reconnaissance purposes, with poor guidance leading to accidental airspace trespass. Others argue that the high number of drones flown into Polish airspace indicates a deliberate act of aggression.

As NATO allies assess how to respond, expressions of condemnation rather than a robust response might encourage further aggression from Russia. The U.S. reaction is also eagerly awaited, as it could significantly influence Western perceptions of security commitments in response to Russia's actions. With all eyes on Poland, this incident stands as a pivotal moment in discussions about future NATO strategies and European security.