Snow, sleet, fog, the lot; when the weather is at its worst is when Russian soldiers tend to go out on assault. After a day and night of steady snowfall, the sky begins to clear just before dawn, during the silent drive to Ukrainian drone positions south of Kupiansk in Kharkiv Oblast.

Ukrainian drones struck deep inside Russia in an overnight attack targeting an oil facility serving a military airfield in the city of Engels, nearly 400 miles from the border, Ukraine’s military said Wednesday.