They murdered 241 American citizens in the bombing of the US Marine Corps barracks in Beirut in 1983. (Only an infantile, ignorant fool would say "Oh, that was Hezbollah, not Iran." Hezbollah WAS and IS Iran. And so is Hamas.)
They directly killed thousand of our servicemen and women in Iraq and Afghanistan.
They made their choice in 1979 to break international laws and norms, so the "We lacked the moral high ground" argument is null and void. The "oh, our hands are not clean" argument goes for every single nation that has ever existed on the face of the Earth.
American hands aren't clean. The Israeli hands aren't clean. The British hands aren't clean. Saudi Arabia's hands aren't clean. Germany's hands aren't clean. Italy's hands aren't clean. The American Indian's hands aren't clean. The Mexican hands aren't clean.
Nobody's hands are clean, and most significantly, Islam's hands are filthily not clean no matter happened at some date or what time a cherry picked point on the calendar. Picking and choosing where you want to deploy that counter-argument makes zero impact on me.
And when Iran attacked our embassy and took American diplomats hostages, they surrendered any right to any pretense of sovereignty under international law.
They made their own choices, not only murdering thousands of Americans, but tens or hundreds of thousands of people all over the world through their proxies (which in Iran's case, means IRAN) in places ranging from Lebanon to Spain and beyond.
Another hard stop at 1979. Go back a little further. (At least fake it.)
Was the coup in 1953 against "international laws and norms" or not?
How does the Greatest Country in the World come off holding other countries to a higher standard than we hold ourselves?