First comes the warning, that disembodied voice over the tannoy: Your attention please. Air siren in the city. Please move to the shelter on the minus second floor. Then comes the mosquito-like whine of the incoming Russian drones, massing in their hundreds just above the clouds. This is the grim reality of night time in Kyiv and other cities across Ukraine. These are attack drones that explode on impact.

However, far from the battlefields of Ukraine, unarmed drones are now buzzing around airports and critical infrastructure in Western Europe. Recent sightings in major NATO member nations like Poland and Belgium have prompted fears that these incidents could be part of a broader strategy of testing Western resolve by hostile actors.

On September 9, around 20 Russian drones overshot Ukraine and entered Poland, leading to airport closures and a scramble by NATO jets to intercept. The incidents highlight the need for heightened security measures, with discussions about establishing a protective 'drone wall' in Europe becoming increasingly urgent.

Despite the lack of explosives with these drones, the questions surrounding their origin—thought to be state-sponsored or proxy launches—remain distressing, especially for nations like Belgium, which host NATO headquarters.

As the threat evolves, experts argue that while defensive measures are critical, addressing the root causes of drone incursions could be vital in maintaining peace and security in the region. In this situation, NATO's capacity to respond will be tested as Europe contemplates how to safeguard its skies against these mysterious airborne threats.