If an autocratic system depends so intimately upon the obfuscation and misrepresentation of facts it can only be imagined that a considerable effort is also and currently going into cultivating retrospective, alternative histories as supporting narratives and aspirationally self-validating reference frames for each and all of these acts of aggression.
It is unlikely that the living memory as persistent cultural presence of those swayed by such constructive disinformation will outlast the material facts as they stand, embedded in space and time.
To believe or not to believe, even and in extremis under totalitarian influence to appear to believe, the truth a deceived people is presented is a transient thing. The material scars and memory of trauma are far harder to erase.
In either case, revisionist histories represent a two-way street and Janus-like communications bridge between truth and falsehood. Being that all fielded diplomatic solutions must successfully cater for irreconcilable difference while simultaneously appealing to compromises that both sides in a negotiation are able to accept, the cost of peace is likely to include an acknowledgement that narrative misdirection by the aggressor will persist.
For this reason, the diplomatic cost may always have to be that the deception upon which the invasion was grounded will remain and be refined as an ongoing weapon of information war, even after hostilities cease. I would usually wax lyrical on the general ineptitude of political solutions in any catastrophic context that are as much a consequence of political (as proxy ideological) belief systems but in this instance it remains as the only plausible way out of this conflict without invoking World War 3.