The drills at a Dutch military base, involving more than 20 countries and some 50 companies, tested cutting-edge systems to detect and counter drones and assessed how they work together.

NATO allies and over 50 private defense companies gathered at De Peel Air Base in the Netherlands on September 19 to test and learn from Ukrainian drone operators and developers who apply their own innovations on the battlefield.

Russian President Vladimir Putin has warned NATO alliance leaders that a move to lift restrictions on Ukraine’s use of longer-range Western missiles to strike deep inside his country would be considered an act of war.