This aerial view shows the Oskil River in Kupiansk district of the Kharkiv region on December 15, 2024, amid the Russian invasion of Ukraine. The Oskil river, which winds into Ukraine's Kharkiv region from Russia, is swept by icy winds and surrounded by expansive snow-blanketed fields dotted with Ukrainian bunkers and zig-zagging trenches. Russian forces crossed it quickly and easily when they invaded in 2022 but were beaten back months later in a rout that embarrassed the Kremlin, but its forces are now sweeping back. (Photo by Roman PILIPEY / AFP)