European nations remain on edge after a recent Russian drone incursion into Polish airspace as Russia and Belarus begin five days of joint military exercises on Friday.

The “Zapad” drills, rehearsing potential clashes with NATO forces, echo the February 2022 exercises after which Russia launched its invasion of Ukraine from Belarus.

Poland and Lithuania, both bordering Belarus, are especially alert given the historical precedent of joint drills preceding military aggression.

Analysts note that past Zapad exercises, including the larger 2021 drills, gave U.S. and British intelligence early warning of Russia’s intentions toward Ukraine, France 24 has reported.

With the war in Ukraine ongoing, NATO members are closely monitoring the current drills for signs of possible escalation or threats to alliance members.