LOL, last week you people were all mad that he was to nice with Russia, a nuclear nation, and now you are mad that he is too strict. He probably shouldn't have written in all caps, but Iran is a threat to everyone. That is all i have to say on the matter
This is not how you deal with a threat, not through twitter, no by doing knee jerk reactions.
You also don't force sanctions after agreeing a deal with them 3 years earlier. Trump is suffocating the Iranian economy but obviously people will blame the regime for everything and ignore what America actually does in the region.