Either the EU manages to step in and largely fill the gap, or Ukraine will have to give in. Russia can then ingest Ukraine, continue to seed political distrust in Western countries and then potentially start another war in Europe a few years later.
Alternatively, the NATO/EU/US may decide to become directly involved in the war in Ukraine to avoid a further destabilization of Europe. In that case, Russia can be beat, although I'd expect Russians to be more motivated to go into war.
I'm not sure whether the way the war against Ukraine plays out has too much influence on whether China decides that it needs to start a war against Taiwan though.
I do still have at least a little hope Ukraine is going to win. A territory does not typically successfully invade another territory a second time. However, I continue to be outspoken for Ukraine. Without aid, Ukraine will probably do what Chechnya is doing and just resort to dirtiertactics, which I'm glad Ukraine is not doing yet.
Ukraine alone won't be the cause for a dystopian scenario with Russia as the world government, but I don't like where it would be going if Ukraine fell. Russia surely wouldn't stop afterwards. I'd rather see a world where trade connects people than a world where governments forcefully connect people via ideologies. The latter never worked out for anyone.
Ukraine will continue to fight for what is rightfully theirs. They've done an outstanding job so far, and it's really highlighted the decline of Russian influence on the world stage. Russia is nothing more than a petrodollar fueled aggressor.
WW3, eventually. The regime won't stop. The ambition is there to rebuild the USSR. That would mean starting a conflict with NATO and, if I'm lucky, NATO will actually involve.
They will lose either way, but they'd have less debts to paid and less things to rebuild.
Also Ukraine will benefit from denazification, the ultranationalism pushed by the ukranian nationalists only brings zero-sum situations for Ukraine and its neighbours not just Russia.
The war will stop, simply put. NATO has been artificially extending this war for far longer than it should have been given the circumstances.
Ukraine had a chance to do peace talks but they blew it trying to have their cake and fuck it too, so now they're going to lose it all.
EDIT: Oh sorry, the way I put it was turning off a lot of people. Let me rephrase that. Ukraine will see that they are all alone in this fight because the US is too busy doing genocide in the middle east and they will tap into their superior Nordic genetics and unlock their superpowers. They will fly through the air and launch the crippled forces of russian ork war crimes into the stratosphere, the remaining will bow down and admit that nazism is the superior form of government as Russia is forced to finally admit they were losing. In short: they will win by a landslide just like all of the western media has been saying all along. EDIT2: WHAT!? I said Ukraine was going to win, what more do you want from me?? EDIT3: I can't believe that worked.
Zelensky will finally have to negotiate and end the war (that is, if he wouldn't get overthrown/killed before that), and millions of Ukrainians will finally get to live without fear of them/their husbands/fathers/etc. getting kidnapped on the streets and being sent to army to die or get permanently wounded.
They will lose months before they would with the aid, but they're still going to lose either way, eventually, like everyone predicted the day this war started before Ukraine, surprisingly, didn't immediately lose.