"I suspect Maliki's motivations are complex and contradictory," said Stephen Biddle, a defense analyst who has served as an advisor to Gen. David H. Petraeus. "The guy is something of an opportunist, trying to figure out what he can get away with, so he thinks it'd be nice to be a dictator for life, but realizes it would be difficult, so he was pleasantly surprised by his hit against [the Mahdi Army] and his probing with the Sons of Iraq.
"If he doesn't pay a price for going against domestic opponents, he'll try more of it," Biddle said. "He is trying to figure out what he can really get."
Much will depend on whether he can use January's provincial elections to consolidate power in southern Iraq. If he manages to expand his reach, it will be a major boost for him when the country holds its next national elections, scheduled for December 2009.
Yet even with his ascension, the limits on Maliki's power are very real: His army remains relatively weak and reliant in the north upon the Kurds. Maliki is also aware of the delicate calculus with the country's onetime Sunni elite, who could revive Iraq's insurgency.
Although he has approved operations against leaders of the Sons of Iraq in mixed provinces such as Diyala in the east, he has been far more careful in the Sunni-dominated province of Anbar, the onetime incubator of the insurgency.
Prominent sheiks involved in the Sons of Iraq there now cultivate him, cognizant of his ability to intercede on their behalf.
A tribal leader, Sheik Ali Hatem Sulaiman, has joined with Maliki in forming a tribal council for Anbar. Other Anbar sheiks describe the prime minister as "the best of the worst" among Shiite leaders, and talk of accepting the new reality in which the country's Shiite majority reigns.
Pivotal to the prime minister's power is his role as the country's military commander. In Baghdad, and several other major provinces, all police and army units formally report first to his office through what are called provincial command centers.
"The prime minister has not hesitated to move around and get involved even in the assignments process in the Iraqi military," the U.S. official said. "I think he is very involved in security policy, he is very involved in security operations."
One of the most controversial military operations in recent months was in Diyala, where the prime minister sent troops from Baghdad who arrested hundreds of Sunni Arabs, some of them associated with the Iraqi Islamic Party, the sect's largest bloc in parliament.