“And what will Russia do if Ukraine accepts these propositions? What security guarantees does Ukraine get?”
Same ones they got when they gave up their nukes.
Did it say anything about Russia’s demand for Ukraine’s complete demilitarization?
As for Crimea, it’s gone; and Russia ain’t giving it back. Self-Rule for the Donbas? I’d agree to that, on the condition it remains part of Ukraine but without a national franchise, and that NO Russian troops remain in ANY Ukrainian territory, which would include Donbas. No NATO membership? I’m okay with that, as well.