"Peaceful solution" so he can proceed with subverting Ukraine the way he was before the Maidan, instead of expending ordnance. Cheaper.
No-one who has negotiated with Russians has ever seen them live up to their agreements. Of course Boris Johnson gave the advice he did.
Putin's expressed objective is the "Russification" of Ukraine. Obliteration of its' borders, its' language, the Ukrainian church, everything. Cultural genocide, on the way to Russky Mir.
As both you and MeganC claim, though neither you have proof of that being the reality. However, had that become the reality then there would have been united support for getting involved including Western Europe. Don't even bother to bring in Neville Chamberlain.
Because it was worth the attempt, even though it failed.
It was then fully understood that, in that case appeasement was just that. However, Hitler had already shown his propensity to take military action, even if the claim was accurate that the majority of the inhabitants were German peoples.
But as it stands now, it is just the two of you, and most likely the rest of the Zeepers, opinion as well. But opinions are not reality. So, it would have been worth finding out what the reality would have been. Instead, we are involved entirely based upon conjecture & opinion. In addition, we would have had undisputed truth that Russia had broken the tenets of the peace agreement.