The problem is you're arguing from an idealistic point of view.
But in the real world might makes right. Doesn't matter what Ukraine wants if it doesn't have nukes to back it up.
USA won't let Russia come near the Americas so that won't happen.
France didn't care that Libya was a "sovereign" nation, neither did USA care about Iraq's sovereignty.
Unfortunately that's how the world works, rules are for the weak nations only. Superpowers don't really care.