I belive that is the whole point- the current regime is on it's way out. Granted, slowly. Even the students that started the revolution in the 70's don't like the current regime. The younger generation really like american pop culture and have an incredible respect for (in theory) our form of government. I can not remember at any time, when Iranians have attacked Americans. Yes, they support groups that are opposed our foreign policies, just as we have supported groups in south america that have done horrible things too. The primary group that Iran supports is Hezbollah, and it is not their stated goal to attack Ameicans. They came about only after the Isreali invasion of south Lebanon, for which the PLO shoulder most of the blame. The attack on the Marine barracks and the US embassy in 1984 are still a mystery, they could just have well been a Christian or Druze group. After all, we shelled the area just east of Beruit pretty heavily a few times, and that is not a muslim area. (NOTE: I lived in West Beruit 1 1/2 years ago not far from where the old US embassy used to be, so I'm not pulling this out of my butt.) Granted, the Iranians stated policy is the destruction of Isreal, but in this region, who's isn't. Even the Iraqi government is leaing that way! If you are going to hand out the lable of terrorist state, look at Syria. They are 100x more of a threat to the world then Iran ever will be. They are actively allowing Jihadis to cross into Iraq, directly causing US deaths. They are constantly egging on the border dispute in the Golhan heights. The provide shelter and administrative support in Damascus for groups that have in the past targeted Americans. And are about to purchase large amount of MANPADS form the russians. Which could easily find thier way into the wrong hands.
Go look through everything you own... See how much is imported. Because you go the isolationist route, goodbye imports. If isolationism was the case we wouldn't be having this debate.