In a stunning reversal of fortunes, Ukraine has successfully defied predictions of a permanent stalemate and advanced on the northeastern front, recapturing large swaths of territory and forcing a chaotic Russian retreat from the area which shows no signs of having stopped yet.
Ukraine has liberated the strategic railway hub of Kupiansk and the stronghold of Izyum, with signs that they could soon retake Svatove and Lysychansk. It's worth noting that Lysychansk was the last major conquest of Russia's "second phase" offensive earlier this year, and Lysychansk is very close to Sieverodonetsk. If Ukraine retakes both, it'll be a signal that said offensive achieved nothing.
While at this point much of the above remains speculation, what we've seen is nonetheless a good sign that Western military aid to Ukraine is paying off. And it's a sign that we ought to give more so that they have a fighting chance of finishing the job.