1. Russia regains momentum and expands its control of Ukrainian territory. Today, most non-Russian military experts discount this possibility, but war is unpredictable. Ukraine would certainly not give up, but it would experience rising external pressure to surrender some territory permanently.

2. Russia holds a static defensive line, probably set back from the current front. (For instance, Russia would probably abandon Kherson and fall behind the Dnieper.) Ukraine would remain motivated to fight, but European support would become more questionable–and US support, too, if Republicans gain control of Congress or the White House. Putin would try to manage his domestic problems by maintaining a war footing and promising success in some undetermined future. The situation might stabilize, with Ukraine continuing to receive some foreign support and Russia managing to protect some of its 2022 gains. Sanctions would remain in place, but Europe would probably import some Russian energy, albeit less than it used in 2021. There might be considerable partisan warfare and perhaps some organized nonviolent resistance in Russian-occupied territory. The situation would be similar to 2014-22, but with new boundaries–and high costs for all.

3. Ukraine continues to make breakthroughs. If Ukraine pushes deep into Zaporizhzhia Oblast, Russian forces in Melitopol, Kherson, and Crimea would be stranded on the wrong side of Ukrainian lines and in deep trouble. In that case:

a) Russia could experience a classic military defeat, as in 1905. Russia and Ukraine might or might not sign an armistice or a treaty, but in any event, the war would effectively end in Ukraine’s favor. Putin might survive by exercising repressive control, or he could be removed and replaced either by a better or a worse leader. The potential would certainly remain for Russia to start a new war later, but “rebuilding” an army that has turned out to be hollow would be a major undertaking.

b) Putin might try to avoid suffering a humiliating defeat at the hands of Ukraine by escalating the conflict to include NATO. That would allow him either to salvage a victory by frightening NATO into demanding concessions from Ukraine or at least save face by presenting the West as his foe. (In that case, he would loosely resemble the Japanese military junta in 1945, who used the atomic bombings to cancel their own pledge to fight to the death). To escalate, Putin could:

1. Attack Ukraine with weapons of mass destruction (WMD);
2. Attack a NATO country with conventional weapons or cyber; or
3. Attack a NATO country with WMDs.

4. At this point, NATO would have a choice about whether and how to respond, ranging from a diplomatic effort to isolate Russia, to a targeted conventional or cyber attack, to a massive military strike on Russia itself. The possible outcomes would range from Putin’s backing down to uncontrolled escalation to WWIII.

I’m certainly hoping for #3a, a straightforward Ukrainian victory. It seems plausible, if only because Putin appears to hope that new troops will turn the tide, and that false hope could keep him fighting until he has simply lost. Again, war is unpredictable, but today’s reports of Ukrainian advances in Kherson Oblast make a victory seem more likely and a Russian rebound (#1) quite improbable. A stalemate (#2) would be harsh and unjust, but it is not difficult to imagine.

Russian escalation (#3b) is very dangerous for the world. I think it would most likely play out as a Russian WMD attack on Ukrainian military targets that prompts a global reaction that is not devastating and that gives Putin an excuse to settle the war. But the other possible results of #3b are all much worse.