The problems with Iran stem further back than the revolution , the royal family were wankers tbf and British and CIA interference with the democratically elected government of mossagdegh and coup that reinstalled the shah ultimately led to the religious extremist gaining a platform and cause to rally people behind against the government.
If the US and us had just left Iran alone after the war, a secular and tollerant ally may be what we have now.
Also this shit kicks off everytime extreme sanctions are applied, and history shows that that tactic doesn't work.
The carrot has seen progress and more peaceful periods in regions.
The stick has seen continued escalation and us going round in circles