I don't believe countries like Iraq, which were artificially created decades ago, will ever become democracies some say they would like to see.
The Iranian regime's interference is not welcome in Iraq either by many Iraqi Shiites - even if help is needed to push back the sunnis (ISIS). Arabs Shiites, have their own unique culture, and most consider Al Sistani as their spiritual leader, not the Iranian mullah Khamenei. I think it is wise for the West to stay out of this mess, at least for now.
DC idealists thought they could get Sunni and Shia to bury the hatchets and get along like good neighbors. Not gonna happen until the end times and then it will be too late.
Ironically, al-Sistani is himself an Iranian.