Iran was in the process of establishing itself as a democracy when the US, in a CIA backed coupe, crushed Iran's fledgling democracy

It's pure speculation that Iran ever would have established anything that resembled a true pluralistic democracy regardless of the CIA's actions.   

Iran, and for that matter Iraq and Afghanistan, have no cultural history of democracy and have never gone thorough an historical period resembling the Enlightenment that created the philosophical foundations for individual human rights and led ultimately to the idea that "governments that derive their just powers from the consent of the governed" as we did in the US. But that philsophical process took centuries. If the CIA hadn't underwritten an Iranian coup, someone else would have, IMO.   

I'm a gardener and one thing I know is that you need the right conditions - soil chemistry, sun, water, etc, - for something to grow.   I don't see the evidence that any of the above three countries have the right conditions to grow democracy.