I wanted to write a compact piece to provide a bird's eye view of the current state and future trajectory of the war and quickly realized that brevity and completeness are incompatible. A list of parts to mention only is long enough: the current state, the players, the short-, mid-, and long-term prospects, the military, political and economical aspects, ... So I restrict the scope to the very skeleton of all these above, with some lumps of meat here and there.
Current state
In recent weeks the Ukrainians have re-gained a huge amount of territory. Putin predictably responded to the new humiliations with some nuclear saber-rattling, which his only patron Xi Jinping demurred. Plus Putin was publicly made to wait in Samarkand at the SCO summit by his supposed allies (SCO is the poor man's NATO of world autocrats). In the West, much furor in the news, and dismissal from the military experts.
The Russians are mostly in retreat, and the Ukrainians are mostly on the advance.
The players
Let's step back and look at the major players in the War.
Ukraine. The Ukrainians have completely stunned the world (even more the Russians, I guess) with their courage, ingenuity, military skills, and national unity. If there was no real Ukrainian nation before the war, as Putin and Western useful idiots claimed (und unbeliveably still claiming), there is now. It's really hard to express what a miracle they did. Their American-trained military is superb and very far from what it was in 2014. Their skill in intelligence operations and media-savviness is at least as remarkable. The resolve to win the war seems unbreakable, but it's also a virtue out of necessity. The war is an existential question for them. Surrender would mean Russian rule, oppression of the society as a whole, and the universal threat of brutal murder and torture to anyone who took arms against the Russians.
As Ukraine became the darling of the West, Russia has become the international pariah of the world. It lost its greatest business partner Europe for good. I severed almost all ties to the high-end part of the global economy. It lost hundreds of thousands of its skilled people who have fled and been constantly fleeing the country right now. It destroyed the myths of Putin and the Russian military might. Nothing like this self-goal has been committed by any country in generations.
China is probably not very happy with the state of affairs. Instead of exposing Western weakness and further strengthening frictions, Russia forged a miraculous unity among their common enemy. And just after Xi Jinping declared Putin his eternal friend or something similar cringy expression of bromance from the old communist vocabulary. Awkward. China nominally supports Russia, but in reality, it doesn't provide much help. It buys its oil and gas at heavy discount (this is the very finite length an eternal friendship goes), and under the threat of Western sanctions it dropped most of its exports to Russia.
On the positive side (for China), it gained a new vassal. Russia is a resource-rich country with a huge potential to make trouble to the West, and it's completely at the mercy of China's goodwill and forever will be. The war might also make China rethink its plans with Taiwan. If the Russians couldn't successfully invade a neighboring country with land borders, how would trying to do that go across a 110 miles wide naval strait?
As for America, the Biden administration's handling of the war has been superb. It combines massive political, financial, military, and intelligence support and restraint. As long as Ukraine keeps its military operations inside its borders, and the Americans are very strongly advising them to do so, it remains a defensive war and the Russian narrative remains indefensible.
The big question is what happens after the midterm elections and especially after 2024? If the sane side of Republicans prevails, the support for Ukraine will continue.
To be blunt and cynical, America has never been given such a geopolitical gift. Putin's fuck-up is beyond the wettest dreams of the hawkiest of American foreign policy hawks. The US received a one-in-a-century opportunity to completely wreck a historical enemy. Its reputation, its economy, its military, without a single American soldier lost, while never losing the moral highground and the support of their allies. All it needs to do is to fund Ukraine, and Ukrainians do the work for it. As H. R. McMaster, Trump's former National Security Adviser blurted out with an almost comically mad laugh in a podcast recently when asked about how America should help Putin decelerate: "Help him decelerate?? Our job is to help him accelerate toward the brick wall!"
Europe. Due to divine (or American) intervention, Europe responded to the crisis with unforeseen and quite amazing unity. Its energy sector is going to be decoupled from Russia for good. In 5 years, people will reliably have forgotten that gas and oil had ever come from Russia. It also stepped on the road to rearmament. All this is mostly thanks to America, without whom the European response to Putin would have been the usual hand-wringing and forced amnesia. Not that the US will ever be thanked for it.
In the time-proven tradition of Western-centric worldview, I lump the rest of the world together as the last actor, mostly because I don't know much about it. The big picture seems to be that Russia doesn't have friends, even among those who loathe the West. Some of these countries have an interest in Russia not losing too badly (like India, who imports half of its weapons from Russia), and some just don't have a dog in the fight. Westerners often find it astonishing how come third-world countries are not as outraged by this war as it's expected from them, but we forget that for much of the world conflicts even bloodier than this are a constant part of daily life.
Predictions
Reading the tea leaves tells me about a protracted conflict for years of varying intensity. The Ukrainian morale and support of the war are through the roof. They just don't have any incentive for giving up. Putin can't afford to give up. The Russians won't topple the regime. It's gonna be a war of attrition for all parties.
In the very long term, the situation will be something like this. Europe won't do business with Russia again. Russia will be a Chinese client. Ukraine will be part of, or an official partner to, the EU and NATO.
With relevances varying based on the length of the war, I think the following factors are decisive:
The things going for Russia
The first is manpower. It's a huge country with a lot of people for cannon fodder. They are demoralized, untrained, and led by mostly incompetent leaders. But there are many of them, and 100,000s can be thrown onto the battlefield every year.
The second hope of Putin is that Europe will suffer a cold winter and the public will force the politicians to take a U-turn, drop the sanctions and stop supporting Ukraine. It's not gonna happen. The gas reserves are 90% full. There is a lot of noise in Europe now saying that yes we are fine this winter, but the next one will be much worse. I think these people simply underestimate the adaptiveness of the world economy. Three months ago Europe was supposed to freeze this winter. We have a full year to prepare for the next. Germany and France will never again trust Russia, and even the voters in general are on the same page.
The third is Donald Trump's return to power. If Republicans don't restrict the support to Ukraine already, a Trump administration would do it. Unfortunately, this can be a game changer.
The fourth is the implosion of the Ukrainian economy. According to some forecasts, Ukraine's GDP will shrink by 35%, while the Russian economy, which has proven much more resilient than experts had thought, will contract by maybe 5%. How much European and American money can fill in the gaps, remains to be seen.
The things going for Ukraine
The first is motivation. The Ukrainians are facing an existential threat. The Russians fight because they are forced to.
The second is ingenuity. Ukraine has taken the upper hand on the physical battlefield and massively dominates in the information war. There surely be ups and downs, but I hope their superiority will last.
The third is the bottomless chests of European and American money and weapons. Russia is a poor country that gets poorer by every month as long as it continues the war. It's depleting not only its financial resources but its weapon stocks as well, without access to technology and imported materials to replenish them. The US will never run out of money and weapons to send.
The fourth is the incompetent opponent. The Russian army reflects Russian society. Corrupt, incompetent, strong only against civilians.
Summary
The most important factor in the war is the American willingness to engage. If the US is fully behind Ukraine, it will still be a long war, but a war of continuous Russian defeats. If it pulls out, all bets are off. So eyes on the elections.