At the core of President Bush's new Iraq policy is an effort to boost Iraqi government control and self-confidence, writes Denis Stauntonin Washington.
President George Bush's new strategy for Iraq is an audacious political, military and diplomatic gamble based on assumptions shared by few outside his administration. The decision to send more troops puts the president at odds with most members of Congress, including many Republicans, much of Washington's military and foreign policy establishment and two thirds of the American public.
His change of course follows the systematic replacement of the team that devised the previous US military strategy in Iraq, starting with former defence secretary Donald Rumsfeld. But it represents a flat rejection of the most important recommendations of the bipartisan Iraq Study Group led by former secretary of state James Baker and former congressman Lee Hamilton.
The Iraq Study Group called for the withdrawal of most US combat forces by early 2008 and direct talks with Iran and Syria on Iraq's future. The president has instead ordered more US forces into a more dangerous combat role than before and deployed warships off Iran's coast rather than sending diplomats to Tehran.
At the heart of the new strategy is a shift in the US military focus from training Iraqi forces to protecting the civilian population in Baghdad and Anbar province in western Iraq. The military operation will be part of a broader counter-insurgency plan with job creation schemes and other economic initiatives aimed at boosting confidence in the institutions of the Iraqi state and the government of Nouri al-Maliki.
Five US brigades - about 17,500 soldiers - will help Iraqi army and police units to restore order in Baghdad and 4,000 marines will fight insurgents in Anbar province.
Mr Bush acknowledged on Wednesday that the operation will mean more American casualties but he argued that the cost of failure in Iraq - starting with the collapse of Mr Maliki's government - would be greater.
"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 revenues 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," he said.
Mr Maliki has assured the president that his government will introduce measures aimed at political reconciliation, including a law that will distribute the country's oil revenues fairly among the Iraqi people. The Iraqi prime minister has also promised to confront Moqtada al-Sadr's Mahdi Army, the most powerful Shia militia, despite the fact that Mr Maliki depends on Mr Sadr's political party for his government's survival.
Mr Bush insists that the US military operation is conditional on Mr Maliki keeping his promises and defence secretary Robert Gates hinted yesterday that the troop increase could be halted if the Iraqis fail to play their part.
Mr Bush's problem as he seeks to persuade Americans of the merits of his plan is that, after four years claiming victory in Iraq, his claim that now, at last, he has found a real strategy for success lacks credibility.
Democrats know that they cannot prevent the troop build-up, which will start next Monday, but public opinion and pressure from party activists are likely to push them beyond merely symbolic condemnations.
Mr Bush's initiative has united Democrats on Iraq as never before and left Republicans fragmented, with up to a quarter of the party's senators opposing their own president.
Mr Bush has won valuable support from presidential hopefuls John McCain and Rudy Giuliani but a number of Republicans facing tough re-election battles in 2008 have publicly opposed the new plan.
Delivering the Democrats' response to the president's address on Wednesday night, Illinois senator Dick Durbin expressed a weariness with Iraq shared by much of the American public.
"America has paid a heavy price. We have paid with the lives of more than 3,000 of our soldiers. We have paid with the sacrifice of our men and women in uniform. And we've paid with the hard-earned tax dollars of the families of America. And we have given the Iraqis so much. We have deposed their dictator.
"We dug him out of a hole in the ground and forced him to face the courts of his own people. We've given the Iraqi people a chance to draft their own constitution, hold their own free elections and establish their own government. . . Now, in the fourth year of this war, it is time for the Iraqis to stand and defend their own nation," he said.
Mr Durbin's analysis may ignore the fact that few Iraqis asked Americans to make this sacrifice but it reflects mainstream opinion, especially among Democratic voters. Many Democrats elected to Congress for the first time last November know that they owe their success to popular disaffection with the war and their supporters expect them to do more than make speeches against it.
Both houses of Congress will vote in the next few weeks on non-binding resolutions rejecting the president's plan for Iraq but these votes may just be the start of a congressional campaign against the war.
In the coming months, Congress will have regular opportunities to attach conditions to funding for military operations, obliging the administration to justify each request in a way that was not required when Republicans controlled both houses. If American casualties increase without clear signs of progress in Baghdad and an emerging prospect of an end to US involvement in Iraq, the president will face more robust calls for withdrawal from emboldened Democrats and disenchanted Republicans who fear for their political future.