Iran could carpet bomb American troops and it wouldn’t break the agreement.
Iran could post on the front of every newspaper in the US “THIS IS THE WORST DEAL YOU GUYS EVER MADE!! SUCKERS!!”
and it would not stop the agreement.
Like that blond said a few months ago, the fact they are holding American captives for no reason doesn’t affect the treaty nor should it.
nobody ever asked why it shouldn’t.
I think that USA are the only ones who are going to sign the agreement anyway. Certainly Iran doesn’t have to sign anything.