BAGHDAD — Ten years after the U.S.-led invasion to oust Iraqi President Saddam Hussein, the geopolitical winner of the war appears to be their common enemy: Iran.
American military forces are long gone, and Iraqi officials say Washington's political influence in Baghdad is now virtually nonexistent. Hussein is dead. But Iran has become an indispensable broker among Baghdad's new Shiite elite, and its influence continues to grow.
The signs are evident in the prominence of pro-Iran militias on the streets, at public celebrations and in the faces of some of those now in the halls of power, men such as Abu Mehdi Mohandis, an Iraqi with a long history of anti-American activity and deep ties to Iran.
During the occupation, U.S. officials accused Mohandis of arranging a supply of Iranian-made bombs to be used against U.S. troops. But now Iraqi officials say Mohandis speaks for Iran here, and Prime Minister Nouri Maliki recently entrusted him with a sensitive domestic political mission.
Iran's role reinforces its strategic position at a time when the world looks increasingly hostile to Tehran, the capital. It faces tough international sanctions for its disputed nuclear program and fears losing longtime ally Syria to an insurgency backed by regional Sunni Muslim rivals.
Western diplomats and Iraqi politicians say they are concerned that the Islamic Republic will be tempted to use proxies in Iraq to strike at its enemies, as it has done with Lebanon-based Hezbollah.
American officials say they remain vital players in Iraq and have worked to defuse tension between Maliki and his foes.
During a visit to Baghdad on Sunday, however, Secretary of State John F. Kerry was unable to persuade Maliki to stop Iranian flights crossing Iraqi airspace to Syria. The U.S. charges that Iranian weapons shipments are key to propping up Syrian President Bashar Assad; Maliki says there is no proof that Tehran is sending anything besides humanitarian aid. Kerry's visit was the first by a U.S. Cabinet official in more than a year.
Overall, Iraqi officials and analysts say, Washington has pursued a policy of near-total disengagement, with policy decisions largely relegated to the embassy in Baghdad. Some tribal leaders complain that the Americans have not contacted them since U.S. troops left in late 2011.
Iraq's political atmosphere has deteriorated. Maliki has ordered the arrest of his former finance minister, a Sunni. Disputes in the north between the central government and leaders of the semiautonomous Kurdish region are unresolved.
"The Americans have no role. Nobody listens to them. They lost their power in this country," said Deputy Prime Minister Saleh Mutlaq, a Sunni, commenting on the disappearance of the Americans as a broker for most of Iraq's disputes.
The vacuum has been filled in large part by Iran and by Iraq's Sunni neighbors, each intent on wielding maximum influence in a country that stands as a buffer between Shiite Iran and the largely Sunni Middle East.
"At the moment, Iran has something akin to veto power in Iraq, in that Maliki is careful not to take decisions that might alienate Iran," said Karim Sadjadpour, an expert on Iran with the Carnegie Endowment for International Peace.
An Iraqi Shiite politician who spoke on condition of anonymity because of the sensitivity of the subject, described Iran's objectives this way: "Controlled instability in Iraq and a submissive or sympathetic Islamist Shia government in accord with Iran's regional interests, most importantly regarding Syria."
Maliki turned to Shiite Islamist parties and figures tied to Iran to stay in power after a close election in 2010. He has fended off challenges since then with the support of Iran's supreme leader, Ayatollah Ali Khamenei, who fears the expansion of Sunni power if Syria or Iraq collapses. Maliki has convinced the Iranians that he is the only one who can hold his country together, according to Iraqi politicians.
Iran has forcefully backed quasi-political and military groups in Iraq such as the Badr Organization, Khitab Hezbollah and Asaib al Haq, and encouraged them to support Maliki.
The Badr Organization was funded and trained by Iran's Revolutionary Guard in the 1980s to fight Hussein. Both Khitab Hezbollah and Asaib al Haq have professed their admiration for Khamenei while declaring their ambition to transform themselves into political and social movements.
Leading Iraqi Shiite officials describe the emergence of such overtly pro-Iran groups as a healthy development after the U.S. military withdrawal.
"These imitators of Khamenei and before that [Ayatollah Ruhollah] Khomeini were in hiding. Now they have become public and known," said Sheik Hamam Hamoudi, a Shiite member of parliament and a longtime resident of Iran before the U.S. toppled Hussein.
At a gathering last month at a sports club, members of Khitab Hezbollah greeted enthusiastic visitors under a portrait of Khamenei and banners showing a fist clenching a black Kalashnikov rifle rising from a map of the Middle East. Guests received a book, graced by a portrait of Khamenei, that describes a war pitting Iran and its allies against the West.
Mohandis, said to secretly head the militia, first rose up against Hussein in the late 1970s. Facing arrest, he moved to Kuwait. A court there later convicted him in absentia of taking part in the bombing of the U.S. and French embassies in 1983.
Mohandis fled to Iran, where he joined the Badr Organization, and he now heads its political bureau in Baghdad. He returned to Iraq after the U.S.-led invasion and was elected to parliament under his birth name, Jamal Jaffar. He fled again when the Americans were alerted to his true identity. In 2009, the Treasury Department labeled him a threat to Iraq's security.
But after the last U.S. troops withdrew in December 2011, he came back.
During the interim, Iraqi officials say, he cultivated a close relationship with Qassem Suleimani, the head of Iran's Quds Force, which is responsible for Iran's relations with Iraq. For any Iraqi official or politician visiting Tehran, Mohandis accompanied Iran's spy chief to the meetings.
In a show of his new prominence, Mohandis was dispatched by Maliki with three senior members of his Dawa Party members to Iraqi Kurdistan last month.
According to those with knowledge of the meeting, Mohandis was sent to try to smooth over a dispute regarding rights to oil-rich Kirkuk and other territory in the north. Mohandis argued for an alliance between the Kurds and Shiites, given regional instability and ongoing Sunni protests in Iraq.
"Mohandis is Iran's Iraqi emissary or messenger," said a senior Iraqi official, who insisted on anonymity because of the topic's delicacy. "When he is in a meeting, people know he speaks for the Quds Force and Suleimani. He speaks for them more than the Iranian Embassy."
Another enforcer of Iranian interests has been Hadi Amri, a hardened militia veteran whom Maliki appointed to the post of transportation minister. In the dispute over Iranian overflights to Syria, Amri and Maliki have ignored U.S. requests to inspect Iranian planes.
The Asaib al Haq militia was blamed for the killing of five U.S. soldiers in 2007 and the abduction of five Britons, four of whom were killed. Sunni Arabs also blame it for some of the worst attacks on their community during Iraq's sectarian warfare.
The Americans jailed the militia's leader, Qais Khazali, but Maliki pushed for him to be transferred to Iraqi custody and join the political process as an alternative to more fundamentalist Shiite groups.
Since his release, Khazali has emerged as a Shiite fundamentalist political force funded, according to his foes and other Iraqi politicians, by Iran. He has organized offices across the country with the aim of recruiting prominent individuals and communities to his cause.