The problem with that is simple: if one side believes they are at war, 2 sides are at war.

And Russia has explained why they believe they are at war, the insane dictator at the top explained that in the 13th century it was really unfair that some army marched from Poland to what is now Chechnya (even Tucker Carlsson frowned as hard as he could and needed about 6 seconds to collect his jaw from the floor) and therefore Ukraine isn't a "real" nation and should be part of Russia. And that, in any case, Russia has the borders it chooses, as does any large country.