Its like 2 dogs fighting, the US wants to win a display of dominance and have the other dog concede defeat - but if instead the other dog is prepared to die, now its a fight to the death and in fights to the death usually both sides die, even if one is stronger. The mentality of "we will just punch them till they capitulate" shows the US mentality, they're not in an existential struggle and they aren't ready to face one.