In the spring and summer of 2022, the war between Ukraine and Russia settled into a stalemate. The firstphase of the war had been a rapid invasion that drew new battle lines across Ukraine; this next phase saw those battle lines harden and change very little over a long period of fighting. But in September, that chapter came to an end. For the first time in several months, Ukraine scored a major victory and won back significant territory from Russia. Ukraine pulled this victory off by taking advantage of a surprising weakness in the Russian army: the difficulty it's had maintaining its ranks of skilled soldiers, especially compared to the training and resources that Ukraine's army has received from its allies.