I would say an absolutist would be justified in crossing the border if they offer that land back at the end of hostilities in exchange for other concessions.
Even if Ukraine doesn’t reclaim all of their land they could offer Russia kursk for some other equal amount of Ukrainian land in any peace talks.
Otherwise if Russia refuses Ukraine is justified in keeping that land.
I would say an absolutist would be justified in crossing the border if they offer that land back at the end of hostilities in exchange for other concessions.
Even if Ukraine doesn’t reclaim all of their land they could offer Russia kursk for some other equal amount of Ukrainian land in any peace talks.
Otherwise if Russia refuses Ukraine is justified in keeping that land.