An idea
How about fully suporting Ukraine with all means, let them take back the Donbass and Krimea.
Ukraine gets back its territory and does some referenda in Donbass etc.
(hard to top Putin's 114 percent pro-russian, but ok make it 115 percent
)
Then internationally accept Ukraine and all of its territory as "annexed" in the borders of pre-2014.
(Internationally meaning all nations sans Russia, North Koea (and maybe China. But only
maybe).)