What do you think of this guy’s analysis ? He was assigned to FMSO as recent as last year I think.

“In the past two years, Iran has sent more than 2,000 students and religious scholars to Najaf and Karbala. About one-third of them belong to Iranian intelligence. It has also assigned representatives in major Shia cities to provide financial support to Shia students and school instructors—$50 to $100 per student and $200 to $500 per instructor. Iran has sent several Iraqi political figures who were living in Iran back to Iraq to infiltrate and obtain sensitive political positions in the new Iraqi government. Iran considers these figures a solid foundation in the process of incorporating Iraq, without its northern area of Kurdistan, the moment the coalition forces start leaving Iraq.”13

In this video interview entitled Former Terrorist of the "Islamic Army" in Iraq Abu Azzam Al-Tamimi: An American Withdrawal Will Spell Disaster - Iranian Occupation More Dangerous, the former insurgent alleges that AQ is supported by Iran (!)

Interviewer: Is there significant Iranian intervention?
Abu 'Azzam Al-Tamimi: Of course.
Interviewer: In what way?
Abu 'Azzam Al-Tamimi: Iran intervenes in every single detail in Iraq.
Interviewer: Whom does it support?
Abu 'Azzam Al-Tamimi: Everybody – it works with the government, with the opponents of the government, with the opponents of the government's opponents, with Al-Qaeda, with the enemies of Al-Qaeda, with the militias, with the enemies of the militias... Iran spreads its investments everywhere – with the Shiites, the Sunnis, and the Kurds.
Interviewer: Al-Qaeda is a Sunni organization, which claims to be fighting those they call "the Rafidites" – how can it possibly cooperate with the Iranians?
Abu 'Azzam Al-Tamimi: Of course it can. How else can you explain the fact that a large number of Al-Qaeda's leaders live in Tehran? How else can you explain the fact that the Al-Qaeda organization targets all the countries in the world – from America to Indonesia, including Saudi Arabia, Jordan, Egypt, Turkey, Algeria, and many others – and the only country absent from this list is Iran, even though it is located between Al-Qaeda's two jaws – Iraq and Afghanistan? Of course there is a very strong alliance between Al-Qaeda and Iran. There is a lot of evidence of this alliance.”
Transcript here.

My principal concern is with the religious lines of communication being utilized by the Iranian clericical heirarchy as a means of infiltrating Iraqi religion, politics, government, industry, constabulary, defense, etc...