If you're being held hostage and you agree not to call the police if they let you go, is that binding? Ukraine should be admitted into NATO the day after any extorted peace deal takes effect.
Protecting Ukraine from genocide is one thing.
Entry into NATO is another.
There will be extremism, terrorism, violence for decades to follow after this blood bath. I am not so sure we should guarantee absolute protection for a nation that has been so ruthlessly slaughtered. For they will be desperately hungry for Russian blood. Ours should be for the protection of life. To step in on a case by case basis, with no guarantee beforehand. To help us avoid encouraging them, if they wanted to do something reckless months and years from now.
We cannot let a thirst for vengeance drag us into any future wars with Russia. The measure of aggression and innocence should weigh on our every action. A rebuilt Ukraine would need to demonstrate that it can democratically function first, and make any necessary concessions to work towards a lasting peace. Absent that, I would not want to give guarantees to the hundreds of thousands who want to avenge loved ones.
Remember, very clearly, this is not over when a ceasefire begins.