Russian troops launch their own attack at the same time, perhaps as a spoiler. On Sunday, Russian and Ukrainian forces launched separate but simultaneous attacks along different axes around the 250-square-mile salient that Ukrainian troops carved out of western Russia’s Kursk Oblast in August.

Simply sign up to the War in Ukraine myFT Digest -- delivered directly to your inbox. Ukraine’s forces are pushing forward in multiple directions in Russia’s southern Kursk region, even as its troops are struggling to hold the line elsewhere along the frontline.