jackk, it might be a coincidence but all amputations of Ukrainian territory happened under Obama and Biden, and not Trump. Georgia did happen under Bush, but there was some resistance shown there.
It is unprovable but seems plausible that if occupation of Crimea were resisted or lead to real consecutives, then Eastern Ukraine might not have happened.
Unfortunately, half measures (such as light symbolic sanctions) seem not to work here. George Bush played Trump at Budapest NATO summit trying to convince others to have Ukraine and Georgia in NATO until he annoyed them. Maybe there will be a new defensive block consisting of US,UK, Eastern Europe, Ukraine, Georgia, Scandinavians, leaving West Europeans to fight their greatest enemy – global warming. I am sure Estonians can accidently cut through NordStream 2 on their own.