I don't see any exit ramp for the US here at this point. The war ends when Iran decides it ends. And from American perspective, it would be a colossal humiliation if they’re forced to run home with their tail between their legs. It would definitively show the whole world that the US is no longer a superpower that cannot be challenged. All their vassals are already starting to realize that they’re expendable, and that the empire can’t protect them. So, a withdrawal would mean a complete collapse of American geopolitical position.