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.

With Russia’s invasion of Ukraine in its fourth year, and the US wavering in its commitment to Western European security, there’s speculation that Russian President Vladimir Putin is testing NATO’s collective security arrangements.

NATO says it's bulking up its defensive posture on its eastern flank bordering Belarus, Russia and Ukraine with new equipment.