Analysis by Gareth Porter*

WASHINGTON, Sep 20 2006 (IPS) — For many months, the George W. Bush administration has been complaining that Iranian meddling in Iraq is a threat to the country’s stability and to U.S. troops. The irony of this publicity campaign over Tehran’s alleged bid to undermine the occupation is that Iran may well be the main factor holding up a showdown between militant Shiites and U.S. forces.

The underlying reality in Iraq, which the administration does not appear to grasp fully, is that the United States is now dependent on the sufferance of Iran and its Iraqi Shiite political-military allies to continue the occupation.

Three and a half years after the occupation began, the U.S. military is no longer the real power in Iraq. As the chief of intelligence for the U.S. Marine Corps revealed in a recent report, U.S. troops have been unable to shake the hold that Sunni insurgents have on the vast western province of Anbar.

But the main threat to the occupation comes not from the Sunni insurgents but from the militant Iraqi Shiite forces aligned with Iran, led by Moqtada al Sadr’s Mahdi Army. The armed Shiite militias are now powerful enough to make it impossible for the U.S.. occupation to continue.

Gone are the days when the U.S. military could be so cavalier about Sadr’s forces that it deliberately provoked a major military confrontation with him in Najaf in April 2004. That was when he was believed to have 10,000 poorly-trained troops.

Since then, U.S. officials have avoided giving any estimate of the Mahdi Army’s strength. But according to a report published last month by London’s Chatham House, which undoubtedly reflected the views of British intelligence in Iraq, the Mahdi Army may now be “several hundred thousand strong”. Even if that estimate vastly overstates his troop strength, it reflects the sense that he has the strongest political-military force in the country – because of the loyalty that so many Shiites have to him.

The Mahdi Army controls Sadr City, the massive Shiite slum in eastern Baghdad that holds half the capital’s population. But even more important, perhaps, it holds sway in the heavily Shiite southern provinces, and as Sadr knows well, that gives him a strategic position from which to bring the U.S. military to a standstill.

Patrick Lang, former head of human intelligence collection and Middle East intelligence at the Defence Intelligence Agency, explained why in an important analysis in the Christian Science Monitor Jul. 21: U.S. troops must be supplied by convoys of trucks that go across hundreds of miles of roads through this Shiite heartland, and the Mahdi Army and its allies in the south could turn those supply routes into a “shooting gallery”.

Lang notes the supply trucks are driven by South Asian or Turkish civilians who would immediately quit. And even if the U.S. military used its own troops to protect the routes, they would vulnerable to ambushes. “A long, linear target such as a convoy of trucks is very hard to defend against irregulars operating in and around their own towns,” he wrote.

It would not require a complete cutoff of supplies to make the U.S. position untenable. A significant reduction in those supplies would begin a “downward spiral”, according to Lang.

Both U.S. officials and the government of Prime Minister Nouri al-Maliki realise that Sadr is too powerful to be dealt with by force. When Iraqi forces raided Sadr City last month accompanied by U.S. advisers, Maliki denounced the operation on television and promised, “This won’t happen again.”

Last week a “senior coalition official” admitted to the Washington Post, “There’s not a military solution” to the Mahdi Army.

But the administration and the military in Iraq still appear to believe that there is some way to contain Sadr’s power. They have not yet accepted that Sadr has both the intention and the capability to bring down the U.S. occupation.

Sadr has made no secret of his intentions. In an interview with the Washington Post published Aug. 11, Sadr’s top deputy, Mustafa Yaqoubi, said, “If we leave the decision to [the Americans], they will not leave. They’ll stay. To get the occupiers to leave, they need [to make] some sacrifice.”

The Shiites have never forgiven the United States for its “betrayal” in calling for an uprising against Saddam Hussein after the 1991 Gulf War and then standing by as Hussein slaughtered thousands of Shiite militants who took up arms. Most of them never supported the occupation in the first place.

Wayne White, principal Iraq analyst for the State Department’s Bureau of Intelligence and Research, recalls that polling done by the State Department soon after the U.S. occupation began but never made public showed that a clear majority of Shiites were already opposed to it.

Growing anger at U.S. military atrocities, combined with a growing sense of power in the Shiite community, have made Sadr’s readiness for a showdown with the U.S. occupation forces enormously popular.

By last spring, the political atmosphere in the Shiite community was seething with hatred of the U.S. and support for war against the occupation forces. In a May 6 story, Borzou Daraghi of the Los Angeles Times quoted a spokesman for the Ayatollah Mohammed Taqi Moderessi in Karbala, known in the past as a moderate, as saying the slogan at Friday prayers is: “Death to America”. The ayatollah reported that people were preparing for a military showdown with the U.S., saying “The Americans won’t leave except by the funerals of their sons.”

If Sadr and his followers are already preparing for a showdown with the U.S. occupation forces, the only factor that appears to be restraining the Mahdi army now is Iran. After all, Tehran’s interest lies not in forcing an immediate withdrawal of U.S. forces, but in keeping them in Iraq as virtual hostages. The potential threat to U.S. forces in Iraq in retaliation for an attack on Iran is probably Tehran’s most effective deterrent to such an attack.

Meeting with Prime Minister Maliki last week, Iran’s Supreme Leader Ayatollah Ali Khamenei said, “We hope that one day the Iraqi nation will regain its rightful place and take the financial and human capital of the country into their own hands with the withdrawal of the foreigners.”

At the University of Virginia a week earlier, former President Mohammad Khatami answered a question on Iraq by saying the immediate departure of U.S. troops would create instability.

It would be surprising if Iran were not urging Sadr to hold off on attacking the occupation forces until after the Bush administration has either reached a broad political agreement with Tehran or has been replaced in two years by an administration that will do so.

Only Iran’s ability to convince Sadr to hold off on his effort to end the occupation can prevent a violent confrontation between Shiite militants and the occupation forces. But Bush’s advisers may still not understand how fundamentally the power equation in Iraq has shifted. “They don’t think like that,” Patrick Lang told IPS. “They think they are still in charge.”

*Gareth Porter is an historian and national security policy analyst. His latest book, “Perils of Dominance: Imbalance of Power and the Road to War in Vietnam”, was published in June 2005.