This is all miles above my pay-grade. so I'm about to make a fool of myself in answering the OP re:reduction of casualties. If I were to make a rough estimate, it seems like by the end of WWI we had gotten a little too good at killing each-other on a global scale. if someone graphed war casualties over time, I should think we might see a temperig of carnage after we went nuclear. of course this fits the whole deterent narrative to a tee, so maybe suspicious. various fronts have still occured and we continue to fight proxies, so the numbers can't be too low... we still purported to fight for freedom (oil) and finding non-extant nukes when we already had access to information and technology voiding said objectives. from my naive perspective it seems like the development of military technology stopped when they fashioned 'a type of bat with a round or oval frame strun with catgut', for protection.