Ukraine has made some impressive progress on the battlefield, but let us hold the applause for a moment: It’s too soon to tell whether Ukraine’s ongoing counteroffensive heralds a Ukrainian victory in the war with Russia, but the remarkably rapid Ukrainian advance on the one hand and the equally remarkable rapid retreat by the Russians on the other do testify to Ukrainian military prowess and, perhaps more critical, Russian military incompetence. It should be amply clear by now that, expert expectations to the contrary, Russia cannot win the war. In fact, the irony is that Russian troops have responded to...