@rosborne979,
But there is a US Embassy in Iran. It's a back office in the British Embassy. Down the corridor, turn right and it's the third room on the left. If the Iranians got wind of it due to carelessness it would explain the recent jamboree at the gates.
An embassy is not a large building with flags waving and reception masts on the roof. Or somewhere to stick a large donor to campaign funds where he's out of the way. It's an old French custom although I don't think they have a monopoly on it. The Romans were too crude with it.
An embassy is such as is sallied forth when a determination to win the hand of the Duke's eldest daughter gets underway. The possibilities ranging far and wide. There's no chance of the US having no embassy to Iran.