but the incursion appeared likely to draw an escalating response from the Kremlin, and its overall outcome remains profoundly uncertain.
That’s the entire point. Force the Russians to over commit. Then pull back. Depending on how involved the Ukrainians want the area to be they might stick to raiding. Or they could be digging in hard behind the raiding right now, making ready to make the Russians pay dearly for every inch. But either way they know it’s temporary.
Unless the Russians fuck it up so badly the Ukrainians don’t need to leave.