The argument is that appeasing Putin in Donbas will work about as well as appeasing him in Crimea, creating successively more damaging conflicts in Europe until Article 5 gets tested and either NATO falls apart or we enter a hot war with Russia, and yeah, that's gonna cost money. You know that this is the point of the WWII comparison, which is why you have so studiously ignored the argument, trying to dodge it harder than neo dodging bullets in the first matrix.
Nobody in America knows what a Donbas or a Crimea is. These all sound like Russian places to me. The names of the places alone sound like they are none of America’s business.