The lesson is there to follow. The Soviet Union fell for a number of reasons. One of them was the patience the US showed to allow Soviet leagers exposure to economic, political, and diplomatic alternatives. Eventually, that exposure caused conflicts within the Soviet hierarchy which allowed western ideas, products, and culture to find their way into the USSR and the people ate it up, demanded change, and got it. That paradigm will work with Iran.

"Generosity. That was my first mistake."
"Experience must be our only guide; reason may mislead us."
"Instagram is Twitter for people who can't read."