The US cannot risk attacking Iran. Historical experience and current strategic developments make this a very low probability.
We know what happened in Vietnam. We know what happened in Afghanistan. For the US, Iran would be an even worse experience than either of those.
Iran's population, national identity consciousness, and doctrines make classic occupation scenarios extremely costly.
Furthermore, after its failures in Vietnam and Afghanistan, the US shifted its preference to proxy wars. They know they are not sufficient for countries of this scale in a direct war.
The US is a bubble, but it continues to control perception management due to the Hollywood effect.
Donald Trump can not you mean?! Because, the US citizens do not want to be involved in a war with Iran with more likelihood to see increased immigrants in their country. We will see what happens in the next few days.
Syria likewise Iraq, we saw over 8000 Americans lost to another war for the sake of Israel. These wars in the middle east are not Americans interest but that of Israel and Benjamin Netanyahu's. Trump being advised to back off from such disastrous attempts but he's chosen to be stubborn regardless regardless.