How can the US withdraw from Ukraine given that they are not fighting there? How can the US negotiate a cease fire in Ukraine over the head of Ukraine? Can you tell me how that is even supposed to be possible? That makes no sense.
I said they should withdraw both politically and militarily. What that would look like is up to whatever agreement could be reached in peace talks. On the other points you're simply being blind to history, read about peace negotiations and you'll find that the parties involved extend far beyond just the combatants especially in conflicts adjacent to super-powers.
Also, who are you talking about when you say "both sides"?Are you talking about Ukraine and Russia? Withdraw to where? Agreement with whom?
Please be specific.