In the sky over western Ukraine, a bullet-shaped P1-SUN interceptor drone dived toward?its target as dozens of soldiers looked on. A cheer went up as it cut through a tow line from another drone to a balloon, which drifted away.

Ukraine’s most skilled military drone pilots squared off this week not against Russia, but against ?each other in a competition to win bragging rights and state-of-the-art hardware for their units.

Drone technology has transformed the war ?in Ukraine. ?Young men using video game consoles to operate strike drones packed with explosives — sometimes from command ?centers far behind the front line — are deeply feared by enemy soldiers.