Ukrainian forces opened a new front in their counterattack against Russia with a breakthrough south of Kharkiv, which has evolved into the fastest advance reported by either side — and one of the biggest shifts in the war's momentum — since the opening weeks of the invasion, Reuters reported Sept. 9. Ukraine likely intends its latest attack to encircle or force the withdrawal of a large group of Russian forces from the area near Izyum, from which Russian forces had threatened the flanks of Ukrainian forces in the Donbas region.