As per usual you start in the middle of the story, do better research... maybe like after WWII, further back even better.
Do you know how many Iranians were killed by Iraq, an American instigated funded war?
Oh right, cause let's see Iraq, Syria, Lebanon, Syria (open slave markets) Afghanistan... yes we see an increase in the Gospel being preached in those countries and wow look at their functioning liberal open democracies.
The US destroyed Iran for oil, they caused this repressive regime.
I agree with your evaluation of history. It's not as black and white as you make out. The first Iraq war was entirely justified. And it was not only the USA that got involved. The problem as I see it is that few Americans have any idea of the culture of the Middle East. Most are tribal and have no interest in democracy. America was the third great power to crash and burn in Afghanistan.
America indeed opened the door to the present Iranian regime. Khomeini was living in Paris when the Shah was forced to leave. He promised a liberal regime and did exactly the opposite. Iran has been at war with America ever since. So this present war is America doing what it should have done decades ago.
The United Kingdom was one of the worst offenders, making deals with tribes and promises that they could not keep. France was not a lot better. No wonder the Middle East is suspicious of the West.
The difference now is that Iran is a threat to the whole world. Iran's Shia regime is religiously bound to destroy Israel. They are waiting for their version of Messiah (false of course) and it won't happen until Israel is destroyed.
Iran is not a Muslim majority country. It is not by nature hostile to the West or Israel. If you think that Iran's regime will not make and use nuclear weapons, you are kidding yourself. This war is an opportunity for a despotic regime to be replaced with something tolerant and without religious zealotry that threatens the world.
No doubt there are a lot of dubious motives behind all this. What matters is the end result. There is also no guarantee that Iran will become a freer nation. I am reasonably sure that there is a much better chance than Iraq or the other nations in the Middle East.
I am also concerned about the prospect of Turkey and/or ISIS taking advantage of Iran's weakness after the war ends. It's a mess and it should never have come to this. It is what it is. Millions of Iranians are celebrating, perhaps prematurely. However, they have much more reason for hope than they did a week ago.
Hope keeps people alive. Some young Iranians committed suicide because they saw no hope and no future except inside an Iranian prison. May God bring down every despot the world over. There are way too many and God's people suffer terribly at their hands.