Though the war is far from over and Russia can find new ways to punish Ukraine, collapsing Russian forces have not only been pushed back; in abandoning their former headquarters in Izium, they also left behind large stores of equipment and ammunition that the Ukrainians can now use against them. Even if the Russians stabilize the line in the coming days, they will be in a far worse position than they were on September 1. Building on months of careful efforts to both prepare Ukrainian forces and waste Russian ones, Ukraine has achieved a strategic masterstroke that military scholars will study for decades to come.

https://www.theatlantic.com/ideas/archive/2022/09/ukraine-russia-putin-kharkiv-kupyansk/671407/