Ukrainian President Volodymyr Zelensky warned Tuesday that his country’s drones would make Russia’s airspace “completely unsafe” for the duration of the war, drawing accusations of “state terrorism” from Russian leader Vladimir Putin. Both sides have intensified long-range attacks in recent months and diplomatic efforts led by the United States remain stalled more than four years into Russia’s full-scale invasion. “Today, we want to warn every airline that uses Russian airspace, every insurer...