After nearly four gruelling years, the war in Iraq may be entering its most critical phase - a surge by American forces that needs results in a hurry, lest the whole adventure be confirmed as the US failure it appears to be.

The US President, George Bush, has claimed repeatedly that victory is just around the corner. Now, he has actually admitted that his strategy was doomed - far from advancing liberty, it has been spreading anarchy. Washington must try a different tack, the President said.

But as Bush aides fleshed out the detail of his new plan over the past 10 days, they robbed the President of the luxury of time. They are demanding policy backflips by the Shiite administration in Baghdad that are seemingly impossible at the same time as they insist on results in a matter of just months.

Thus Bush is setting the stage for a critical milestone, not just in the Iraqi conflict, but also in the global war on terrorism which he launched in the immediate aftermath of the September 11, 2001, attacks on New York and Washington.

Any lingering doubts that the US-led coalition forces in Iraq are hostage to religious, ethnic and tribal forces beyond their control will evaporate unless Bush's new 21,000-strong US troop deployment can impose a genuine sense of law and order and real security. Their failure in Baghdad would make it very difficult for Bush to deny that he has failed in Iraq.

Despite all the partisan rhetoric and brinkmanship in Washington these days, that will be a defining moment in US history - because, whether they are Republican or Democrat, few in Washington would be able to stomach the many ugly consequences of being seen to be surrendering by ordering the American troops home.

Those consequences? Even more intense civil war as the country's security forces abandon the last vestiges of loyalty to a national government and, instead, line up with the militias already fighting for their own ethnic or religious quarter. In the best-case scenario for the region, neighbouring countries might just fund, arm and train their co-religionists in Iraq; in the worst, they will send troops and machines for what will become a Shiite-Sunni war that will throw the region - and global oil markets - into crisis.

Tip-toeing around the civil war that has already begun and staying "mum" on the irreparable damage that would be done to US credibility in the eyes of the world, Bush himself outlined what he said would be the consequences of US failure in Iraq: "Radical Islamic extremists would grow in strength and gain new recruits. They would be in a better position to topple moderate governments, create chaos in the region and use oil revenue to fund their ambitions.

"Iran would be emboldened in its pursuit of nuclear weapons. Our enemies would have a safe haven from which to plan and launch attacks on the American people."

Some halfway houses are being canvassed for the Americans - a retreat to bases in "safe" areas of Iraq that would maintain a US presence while Iraqis sorted out their own mess; or a retreat to bases beyond Iraq, but in the region.

But beyond the Iraqi furnace, any of those will be enough for "victory" claims by Islamic jihadis that will have great resonance as a tool of global terrorist recruitment.

Inevitably, too, anything approximating an American retreat in Iraq would be a massive morale booster for the Taliban and al-Qaeda, which now are fighting more determinedly than at any time since the fall of Kabul. There is a very real risk of an explosion of terrorist and insurgent violence in Afghanistan that will demand a huge new deployment back where it all started at the end of 2001.

Such a prospect was underscored this week when the new US Defence Secretary, Robert Gates, finished a round of meetings with his generals in Kabul by declaring he was "strongly inclined" to send more US troops to Afghanistan because of a three-fold increase in insurgent attacks in just over three months.

All this would unfold in a region that is even more unstable than it was before September 11 - unshackled by the defeat of Sunni regimes to its immediate east (Afghanistan) and west (Iraq), Shiite Iran is in the ascendancy; Iraq is Shiite-controlled and Shiites in Lebanon and elsewhere are flexing their muscles.

Sunni regimes in Saudi Arabia, Egypt and Jordan are alarmed by all this Shiite thrusting which, for them, is the most troubling of the unintended consequences of the Bush invasion of Iraq. But there is also a "we-told-you-so" smugness in these autocratic Sunni capitals because, given developments, they don't expect too much more of this democracy nonsense to be thrust at them by Washington.

Just as aspects of the Bush case for invading Iraq didn't add up, commentators have found credibility gaps in the President's planned Baghdad surge. Bush billed it as an Iraqi solution to the crisis, but it has been widely reported that the Iraqi Prime Minister, Nouri al-Maliki, demanded a lower US profile - not the higher one on which Bush is pinning his hopes. Bush also said the plan had the support of American generals, but in November the commander of US forces in the Middle East, General John Abizaid, told Congress that extra troops were not needed.

Perhaps Bush's greatest departure from reality was his warning that if the Iraqi Government did not deliver it "will lose the support of the American people". He appears to be in denial about countless opinion polls and the result of the November midterm elections in the US, all of which confirm that that support is already lost.

Also, for reasons that have never been explained since the former defence secretary, Donald Rumsfeld, insisted on a pared-back invasion force in 2003, the numbers don't add up.

A new manual for the US military estimates that, to be effective, a counterinsurgency force requires at least one soldier for every 40 or 50 inhabitants. But for Baghdad and the adjacent Sunni Triangle alone, that would require about 130,000 more troops - not Bush's promised 21,000.

The ability of 20,000-odd US troops and their Iraqi helpers to make any difference to the mayhem of the capital was put in perspective late last week when the joint forces again attempted to tame Haifa Street, a single thoroughfare in downtown Baghdad: 1000 troops were required.

In the same vein, when the Americans doubled their forces to 15,000 and brought an extra 9000 Iraqi troops into Baghdad last year, there was a 20 per cent increase in the rate of attacks - a rise that some senior US officials attributed to the fact that more American troops meant more targets for the insurgency.

Likewise, relations between the US generals and their Iraqi counterparts are far less rosy than Bush would have had his audience believe when he unveiled his plan last week.

Acknowledging the ever-present Shiite fear that the Americans are trying to rob them of power and resources in a country in which their majority status has been confirmed at the ballot box, a frustrated US officer told The New York Times this week: "We are implementing a strategy to embolden a government that is actually part of the problem. We are being played like a pawn."

The Americans are itching for a showdown with the Shiite militias - especially Moqtada al-Sadr's Mahdi Army, which is melted into the fabric of Sadr City, a district identified by Gates as a definite target in the new security campaign. Given the uncertain loyalty of the Shiite-dominated Iraqi security forces, that could be a fraught contest.

But in a move that confounded some observers, Bush also seemed to be setting the ground for open confrontation with Iran - he has sent a second navy carrier battle group to the Persian Gulf and warned Tehran that US forces in Iraq "will seek out and destroy the networks providing advanced weaponry and training to our enemies in Iraq".

In the days after the speech, US forces in Iraqi Kurdistan seemed to be deliberately picking a fight when they raided an Iranian building in the northern city of Irbil, arresting six Iranians whom they described as "foreign intelligence agents working with Iraqis to destabilise Iraq and [to] target coalition forces".

The smacking came not from Tehran, but from Baghdad - Iran was a neighbour and trading partner and the six were diplomats known to Baghdad whose office was in the process of being given consular status.

This is high-risk stuff from Washington - because the likely outcome is further alienation of the Shiite establishment in Baghdad, many of whom remain grateful to Tehran for sheltering them during the Saddam years.

Some US officers in Iraq suspect their President has been a victim of Iraqi double-speak in his belief that the Baghdad regime will allow an even-handed security approach in Sunni and Shiite districts of the capital.

Until now, Maliki has blocked US incursions into Shiite areas - especially the slum quarter of Sadr City which is the power base of the renegade Sadr, on whom Maliki depends for the votes of his 30-odd member bloc in the National Assembly.

The Americans rate Sadr's Mahdi Army as the most lethal and disruptive of the militias in Iraq. But Maliki's supporters insist that the Shiite militias only mount retaliatory attacks and if the Americans would just stamp out the Sunni insurgents there would be no attacks to demand Shiite retaliation.

Maliki tried to talk tough on Thursday, claiming that his forces had recently rounded up more than 400 Mahdi Army members. But he was flatly contradicted by a senior spokesman for the Sadr militia.

It all leaves some Shiites wondering if the Americans are attempting to set Maliki up for a fall. A Shiite political figure laid it out for The New York Times: "[Maliki] can't disarm the militias. He can't deliver a good program for the economy and reconstruction. He cannot deliver on services. This is a matter of fact - there is a common understanding on the American side and the Iraqi side."

Perhaps the biggest obstacle to American hope in Iraq is the concrete walls of distrust that have been thrown up - majority Shiites who welcomed the Americans in 2003 have become suspicious of them; minority Sunnis who spat on the Americans in the days after the invasion now want them to stay; few ordinary Iraqis trust anyone in a uniform of the Iraqi security services - especially that of the Iraqi police.

Also, there is neither the trust nor the mutual respect between any of the key religious and ethnic groups necessary for any political accommodation that might be built on the back of a successful military campaign. No matter the phase of the post-Saddam era - US occupation in 2003, a raging Sunni insurgency in 2005, a Shiite-dominated government in 2006 - the Shiites have refused to compromise on issues that might convince Sunnis they have a viable future in the new Iraq.

The best Bush can hope for is that the "surge" will buy him time - but that is a false dawn. His aides are already warning the Iraqis that off-ramps have been written into the "surge" plan to allow the Americans to abandon the new deployment if the Iraqis don't live up to their side of the deal.

And then what - blame Tehran?

American experts such as Stephen Biddle, the author of Military Power: Explaining Victory and Defeat in Modern Battle, fret about a long-term crisis that could involve Iranian nuclear weapons.

But bad as it was, his most likely scenario when he spoke to reporters last weekend was less calamitous: "We get out - the civil war escalates. It's funded by all [the neighbouring countries], but they don't send their troops across the border. The war just bumps along for five or 10 years and everybody eventually gets so weary that diplomacy finally gets going and there is a ceasefire, power-sharing deal.

"During that period, Iraqi oil output crashed, there is huge instability in the region and oil prices rise."

Almost as an afterthought, he said: "And there's a humanitarian catastrophe in Iraq."

Copyright © 2007. The Sydney Morning Herald.

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