Unless Zelensky can make a deal where Russia withdrawals from all of the conquered territory, he is facing an imminent military coup, I don't think his generals are thrilled with him and are only distracted right now by their hate for Russia. Once the threat is "gone", the disgruntled military apparatus will turn on him and his government.
Assuming Ukraine/EU caves, my prediction is that Russia keeps the territory they have gained, and to sweeten the deal, they get everything east of the Dnieper. In exchange, Russia agrees to an economic agreement with the USA and ensures the EU gets natural gas. Western Ukraine joins NATO or at least given explicit security guarantees, after which regime change is carried out possibly ending with a new parliament or even a junta, which will be a complete puppet of NATO.
The bottom line is Russia can fight this war longer than Ukraine, at least from the perspective of economics and manpower. If the USA pulls out entirely, Ukraine's military weakens until by the end of the year they are at a point of collapse, in which case ANYTHING is considered favorable. Zelensky should have bitten the bullet and accepted he is not in a position to argue anything at this point unless he can demonstrate his military is still capable of routing the Russians like they did two years ago, otherwise, America is burning military equipment for a lost cause.
