The President said that he understood why many Americans had had their confidence in the war shaken after watching scenes of carnage on television. He was speaking in Cleveland, Ohio, a state where his support has plummeted faster than any other in recent months.

Mr Bush cited Tal Afar in Iraq as a model for a new strategy of “clear, hold and build”. The city had been cleared of insurgents only for an “horrific” enemy to return. But the US had sought to win the trust of the local population, leaving behind well-trained Iraqi troops and a strong civic government, he said.

“The last three years have tested our resolve. The fighting has been difficult. The enemy we have faced has proved to be brutal and relentless. We’re adapting our approach to reflect the realities on the ground. The strategy which worked in Tal Afar did not come overnight; it came after much trial and error.”

Mr Bush added: “I wish I could tell you that the progress being made in Tal Afar is the same in the rest of Iraq. It is not.” The President also said that more sacrifices were necessary, adopting Churchillian rhetoric. “We will fight them in Iraq; we will fight them across the world; we will stay and fight until the fight has been won.”

But the President’s definition of victory in Iraq has undergone subtle changes since he declared Iraq to be free aboard USS Abraham Lincoln three years ago. Whereas two years ago Mr Bush was talking of defeating the insurgency, he has become more cautious.

Yesterday’s speech referred to the “insurgency becoming marginalised”, while last week he emphasised the training of Iraqi forces.

His chastened political circumstances were also apparent in questions from his audience yesterday.

They included being asked how voters could trust leaders who had led them into Iraq with claims that Saddam had weapons of mass destruction, as well as trenchant criticism of the cost of war.

Mr Bush also reiterated that the US would use force if necessary to defend Israel from Iran: “We will use military might to protect our ally.”

John Reid, the Defence Secretary, admitted that the insurgents were becoming ever more “barbaric and cruel”.

But Mr Reid, who returned yesterday from a visit to Iraq, rejected suggestions that the Iraqi people were worse off than under Saddam Hussein. Nor, he said, was it sliding into civil war.

He refused to give any timetable for the pullout of the 8,000 British troops in Iraq, effectively dismissing the prediction by Lieutenant-General Nick Houghton that the bulk could be home by the end of 2008. He said: “We will base decisions on improved conditions on the ground, and that means a lower level of insurgency and a higher level of Iraqi (security force competency.”

WORDS THAT FAILED TO WIN THE WAR

“In the battle of Iraq, the United States and our allies have prevailed . . . Because of you, our nation is more secure. Because of you, the tyrant has fallen and Iraq is free.”

May 1, 2003, on board USS Abraham Lincoln, the so-called “Mission Accomplished speech”

“All of us can now agree that the fall of the Iraqi dictator has removed a source of violence, aggression, and instability in the Middle East . . . Men and women across the Middle East, looking to Iraq, are getting a glimpse of what life in a free country can be like.”

March 19, 2004, on the first anniversary of the invasion

“The plan for Iraqi democracy is to help establish the stability and security that democracy requires. The terrorists, illegal militia and Saddam loyalists stand between the Iraqi people and their future as a free nation.”

May 24, 2004, Carlisle, Pennsylvania

“Our goal is to train enough Iraqi forces so they can carry the fight.”

November 30, 2005, US Naval Academy, Maryland

“Victory will come when the terrorists and Saddamists can no longer threaten Iraqi democracy, when the Iraqi security forces can provide for the safety of their own citizens on their own and when Iraq is not a safe haven for terrorists.”

In Cleveland, Ohio, yesterday

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