The Ukrainian major had a few tasks to complete as he made the rounds along his army battalion’s front line. One platoon commander needed anti-tank weapons. Another wanted to show off a new line of trenches his forces had dug following a recent Ukrainian advance.

But as he drove between positions in his camouflaged armored van near the town of Derhachi, the clock was ticking. A Russian surveillance drone hovered above, watching, sending back coordinates to Russian artillery units, the major said. About 20 minutes later, at least three shells rained down, forcing the major and his team to scramble.

"They’re getting better,” said the major, named Kostyantyn. "They know our positions, but they saw the car coming and started to fire.”