I know Ukraine will not and cannot do this, but writing off it's East and Crimea would enable NATO membership and EU ascension.
No, it wouldn't.
NATO deciding it was willing to piss off Russia (which is why, without those active conflicts, Ukraine and Georgia were denied MAPs in 2008) would allow NATO membership. There's no actual rule that would prevent Ukraine from joining during the invasion (and even if there was, any NATO rule can be changed, either in a general way or to add a sui generis exception, by the same group -- all NATO members agreeing together -- required to admit a new member under the existing rule, so the rule would not actually be an additional barrier.)
"But," you might object, "even if there is not a rule preventing it, Ukraine joining while the Russian invasion continues would be impractical because it would immediately trigger Article 5, as long as Russian forces were engaging Ukrainian forces anywhere in the country, or even occupying any part of the country."
That could be managed, though, by admitting Ukraine while adopting either a general (for later review) or temporary with explicit time limits or other terminating conditions exclusion of some parts of its territory from Article 5 (not all the territory of all NATO members is covered by Article 5 now.)
Ukraines problems are logistical and attrition and they have very strong NATO support. The red lines about prodding Russia will still exist and the supply shortages across the EU will as well.
Joining NATO makes sense in peace time and so diplomats can hang out at conferences and get formally connected to intelligence data. But how different is that to the data feeds Ukraine gets today?
Depends on the terms.
If, say, Article 5 excluded defined territories whose control was actively contested at the time or which were occupied by Russia with an explicit time limit, and applied fully to the rest of the country (including places Russia likes to lob missiles but cannot yet effectively contest for control of), that would pretty substantially change the Russian calculus of the war.
And especially if it also came with the kind of forward deployment (to the covered part of Ukraine) of NATO troops made to other eastern-flank countries, it would free up Ukrainian forces to deal with the contested and currently-occupied areas.
For example, fostering trade of military goods and technologies between members (especially for the USA as a major exporter) and smoothing out their national budgeting since it's kind of like buying insurance.
2008 is not 2024.
1. It suggests that there's a distinct objective/legalistic blocker to Ukraine's membership, when in reality the bar is "whatever existing NATO members want."
2. Even if #1 and Ukraine tried it, the benchmark is fundamentally unfair/unrealistic/unworkable. In this particular case, Putin would instantly declare-ownership over more Ukrainian territory, over and over, indefinitely.
If anything it's the opposite: There's no point trying to avoid provoking Putin because (A) he's a dishonest actor and has/will feign a grievance for any reason that benefits him and (B) Ukraine from forming alliances with its neighbors is one of his primary goals, so it's impossible to get that with land-deals or conciliatory gestures.
Even if that meant that NATO would be in direct conflict with Russia, then it would be solved between NATO and Russia.
>2. Even if #1 and Ukraine tried it, the benchmark is fundamentally unfair/unrealistic/unworkable. In this particular case, Putin would instantly declare-ownership over more Ukrainian territory, over and over, indefinitely.
If sovereign countries' security depends on what delusional dictators write on a piece of paper, then this isn't much of a world worth living in.
Long story short, Putin can claim whatever it wants, in the eyes of the UN, Ukraine has its 1991 borders and that's where they should remain no matter what - even if it means a direct conflict with NATO. Enough with this bluff bullsht.
Are Russians, who live in one of the largest countries in the world filled with resources, going to commit collective suicide because of Ukraine?