While his name is always accompanied with the statement that Haider al-Abadi is a member of the same political coalition (State of Law) as Nouri al-Maliki, it is curiously understated or omitted that he is actually a member of the same party, Dawa. From the point of view of the Iranians, this makes Abadi a lateral transfer.

Maliki was the first prime minister to succeed the “provisional government.” Whether he was a chosen Iranian proxy, or an accidental compromise, is open to question. On the one hand, the C.I.A. interviewed four candidates, with the intent of screening out Iranian influence. Opposing  the C.I.A.’s diligence  was the bond of a religion identical between Iran and Iraq’s Shiites, and political actors who have had extensive periods of residence in both countries, with personal associations of a lifetime.

This kind of setup fosters double agents, not flipped over lunch-cum-blackmail, but cultivated over many years.  So, with all due respect to the C.I.A., I don’t think they could have accurately understood the situation and penetrated the relationships. The Shi’ite bond between Iraq and Iran will always be a hall of mirrors to us. And so the idea that the U.S. successfully engineered the rejection of the supposed Iranian favorite, Ibrahim al-Jaafari, in favor of Maliki, is questionable. Quoting from the Wikipedia article,

United States Ambassador to Iraq Zalmay Khalilzad said that "[Maliki's] reputation is as someone who is independent of Iran." Khalilzad also maintained that Iran "pressured everyone for Jaafari to stay".[7] More recently, however, it has been claimed that al-Maliki was the preferred candidate of Qasem Soleimani, the commander of the Quds Force, and that it was Soleimani who brokered the deal between senior Shiite and Kurdish leaders that lead to his election as Prime Minister.

As Meredith Wilson  observed in “The Music Man”, you gotta know the territory.

Since Maliki’s successor is also drawn from Dawa, the open-source hunch is that there is something special about the party. Statements are made that that Dawa receives financial support from Iran. Although past support seems likely from Dawa’s history, which intertwines with the Iranian Revolution, I can’t find a a reasonable citation for the present.

One significant point of conflict exists between Iraq’s Dawa and Iran’s Qom religious establishment, and it is rather severe. To the Western mind, this might discredit all thoughts of Dawa as an instrument of Iranian subversion. More on this later.