I would propose that matter be approached removed from the context of the war. Accept that the normal is the war and then go from there. That means that we don't let the Russians or Ukrainians accuse, bicker or complain but rather accept that status quo of this moment and work backward to how we can ensure that nothing else is shot by either side at this piece of earth. If it requires offering some humantirian aid to the Russian soldiers, maybe even make an investment in better barracks for which ever country at the moment of the accord is in power, then so be it. Most likely, it will also require talking tough to Kiev. Tell them, this is how it is going to be and there can be no military acitivity for X number of kilometers around this spot regardless of how much they want to retake it. This "screw up" will affect the whole world and millions of people and not just the criminally-responsible aggressor and the victim nation.