Came across this, 'special report,' on Yahoo. I did not know that the leadership of the most effective militias in Iraq are led and supplied by Iran. After the almost decade long war in the 80's, I did not think that Iraq and Iran would have common ground to eat a meal nevermind have Iranian military leaders organizing and leading Iraqi militias. Apparently, it's the Shi'ite in them. In response to the Sunni Daesh (Islamic State), Iran has actively organized the Iraqis and fought the terrorists. And seem to be doing quite well! More at the link:
http://news.yahoo.com/special-report-irans-military-chiefs-operate-iraq-102350689.html
Never underestimate the schism between Sunnis and Shiites. It goes deeper than the racial divide between Arabs and Persians.
Without a strong centralized secular government in Baghdad, it's open season for Iran to provide aid, support, etc. to Iraqi Shittes who are beleaguered by Iraqi Sunnis.