"Eastern Sentry is not just a new initiative – it is a clear signal: NATO’s borders are inviolable, and the security of our citizens remains a priority," Poland's General Staff wrote on X.

By Alan Charlish, Lidia Kelly and Barbara Erling WARSAW/WYRYKI-WOLA, Poland (Reuters) - Poland shot down suspected Russian drones in its airspace on Wednesday with the backing of aircraft from its NATO allies,

Russian drones breached Poland’s airspace and, experts said, by Kremlin design or not, the incident tested NATO’s readiness to defend its easternmost members.

Alarms bells sounded this week in Europe after NATO jets scrambled to intercept an unprecedented Russian drone incursion in Poland. Now there is fresh unease on NATO’s eastern flank, as Russia and Belarus kick off major military drills to test the readiness of their armed forces.

Polish Prime Minister Donald Tusk told parliament it was "the closest we have been to open conflict since World War Two."

Kyiv fears that Europe will react to Russia’s drone incursion into Poland by keeping its air defenses to itself instead of helping embattled Ukraine.

In the years since Russia invaded Ukraine, NATO has focused on defending its own territory first and resisted lower-level harassment from Russia, like acts of sabotage and intimidation