Wouldn't Turkey or someone sour this?

But if it's actually possible, that's fascinating... if Ukraine can't push back quickly, wouldn't it "force" an end to the war? Russia would have a red line it absolutely can't cross, no hope of advancement, and likely just claim everything on the other side. Surely they wouldn't continue a grinding stalemate where Ukraine has a "safe zone" to operate out of.

If Ukraine does retain its ability to push back hard by the time this happens, and doesn't go for a truce, then that's especially peculiar. Walling off a part of their territory as actually untouchable seems like a massive strategic advantage for Ukraine.

Just because everyone would be drawn into war doesn't mean they can't join. It just makes it so everyone is less likely to agree. if russa attacks a nato member (the baltic states?) Nato will bring ukraine in quickly because then they are already at war an ukrain has too many useful places to launch an attack on russia from.

There has never been a clause about territorial integrity as a prerequisite for membership in the NATO treaties, that was just something made up by the Obama administration to appease Putin and get him to stop being paranoid about Georgia and Ukraine joining NATO.

I'm not saying that that wouldn't work, but that seems like an excessively-complicated bit of lawyering.

If the goal is to provide NATO guarantees for part of Ukraine's territory, but not to provide guarantees for another part of it, to counter Russia playing the "as long as I control part of your territory, you can't join NATO" bit, the only thing that produces the guarantee is what's on the paper of the NATO Treaty.

That treaty text is not written in stone. As long as all the members -- and this assumes that we can avoid excessive shennanigans of the sort that Hungary and Turkey did around Sweden and Finland joining -- are okay with it, the treaty text can be revised to say whatever. Yeah, you need unanimity for any such revision, but you need unanimity anyway to add a member, so the bar is no different from having Ukraine join in any other way.

NATO Treaty Article 6 defines the scope of Article 5 coverage.

https://www.nato.int/cps/en/natohq/official_texts_17120.htm

Article 6

For the purpose of Article 5, an armed attack on one or more of the Parties is deemed to include an armed attack:

• on the territory of any of the Parties in Europe or North America, on the Algerian Departments of France, on the territory of Turkey or on the Islands under the jurisdiction of any of the Parties in the North Atlantic area north of the Tropic of Cancer;
• on the forces, vessels, or aircraft of any of the Parties, when in or over these territories or any other area in Europe in which occupation forces of any of the Parties were stationed on the date when the Treaty entered into force or the Mediterranean Sea or the North Atlantic area north of the Tropic of Cancer.

In the original treaty, the bit about Turkey -- much of Turkey's territory is outside Europe -- was not present. When Turkey joined, we did a small revision to extend NATO coverage -- which originally did not cover territory outside of the Mediterranean, North Atlantic, Europe, and North America at all. Even today, the treaty does not guarantee against attacks on European territories like New Caledonia or American territories like Hawaii.

Honestly, I think that there may be a very legitimate argument that given that Romania and Bulgaria joined -- and this becomes even more-significant with a Ukrainian membership -- that the scope of Article 6 should be extended to the Black Sea, as we did with Turkey when Turkey joined. Otherwise, it's possible for Russia to perform a blockade on NATO Black Sea powers and sink their warships without them being able to avail themselves of NATO Article 5 protection.

Oooh can we do Cyprus next then? What do you mean no?

Would Ukraine becoming a NATO member grant all other members having to attack Russia? Not necessarily a bad thing, but would mean WW3.