Along Ukraine-Belarus border, a war of nerves — and drones

Belarus border, Ukraine: Reconnaissance drones take off several times a day from Ukrainian bases deep inside the dense forest, marching across the border into Belarus, a close Russian ally, scanning the sky and ground for signs of trouble on the other side.
Ukrainian units are monitoring a 1,000-kilometre (650 mi) border of marsh and woodland for a possible surprise invasion from the north, almost a repeat of the failed Russian thrust towards Kyiv at the start of the war a year earlier.