And what, pray tell, is the alternative here? A surrender to Russia is tantamount a full on capitalisation of the west and a defacto encouragement for Putin to keep pushing aggressive expansionist agendas. Ukraine will have an ongoing border dispute that can turn violent at any time with an adversary that’s been emboldened by a proven lack of support by Ukraine’s allies.
There is no winner in war, but this would be about as close to winning as Russia could possibly get.