The US supported both sides in the Iran/Iraq war. Iran was and is our enemy. We would have been fully justified by international law for going to war with them for the invasion of our embassy. Embassies are Sovreign territory, territorial enclaves that are legally part of the owning country, NOT the host country. We played both sides against each other, to keep both weak and divided so they were no threat to anyone else in the Middle East. Look at what happened when we stopped distracting them. Iran became the most prolific sponser of terrorism, far outdoing Ghaddafi and Iraq started invading its neighbors.