Entirely guessing here, but I suspect the US is working towards a traditional compromise settlement that makes no one happy and sets the stage for another conflict down the road. Probably with the Ukraine recovering to the post 2014 border, but leaving Crimea unrecovered, possibly with the suggestion of a UN governed referendum (which will be indefinitely put off) to determine it’s final status as a territory.
The Ukraine will be unhappy, but dependent to a large degree on Western support for recovery, and will still have the majority of the win, and Russia will be unhappy (obviously) but won’t have lost ‘core’ territory from their POV, and might be willing to settle.
And of course, it’ll blow up again down the line, but the USA is bad about going for quick fixes.
I don’t think this is the likely outcome, just a plausible scenario that they think they can get everyone to just barely tolerate, ideally before use of nuclear weapons pushes any hope of a negotiated solution off the table (probably).
One of the the things that will also probably kill any long term peace prospects are the non-governmental losses that are going to be pursued by all parties in the courts. Russia is never getting back it’s funds - from the airlines claiming damages for seized planes, to other internationally owned resources, to Ukrainian governmental and civilian claims, Russia’s future trade with the West is going to be crippled for probably at least a decade.
Which will per historical trends, just make the populace unhappy, and looking for someone to blame, and someone to ‘make it right’. So meet the new boss, same as the old boss. 