That's true, but also irrelavent.
USA probably could do these things if they tried, given enough time and resources. It seems pretty clear that Trump doesn't want to spend the resources (and lives) required to do so. Hence negotiations. Iran probably sees that the war is incredibly unpopular in USA and figures trump lacks the political capital to continue, so they are probably trying to drive a hard bargain. In turn, Trump might in turn decide continuing is cheaper than the onerous terms iran wants and continue the war.
I predict more war, since as much as this war is politically bad for trump, he also hates "losing".