A lot would change for a few, not for the 8b people on this planet.

I am considering the absolute impact on those affected, which is the most relevant for this discussion. Millions are not "a few". And it's absolutely unnecessary, the aggressor has always been in the position to pull back and leave (or not attack at all). Everyone but _a few_ war profiteers suffers from war, because it requires hours of work (weapons) diverted towards destroying other hours of work (cars, houses, infrastructure), occupying workers' time by ordering them to kill future workers, all of which could go towards increasing production instead of decreasing it, which does affect global markets and thus people globally.