Despite the violence and the collapse of his two main reasons for the war, Bush unapologetically told sceptical leaders at the UN General Assembly on Tuesday that they owed support to Iraqi Prime Minister Iyad Allawi's fledgling government.
"The government of Prime Minister [Iyad] Allawi has earned the support of every nation that believes in self-determination and desires peace," said Bush, who was to host the Iraqi leader at the White House on Thursday.
Later, Bush and Allawi denounced the beheading of US captive Eugene Armstrong by armed men in Iraq while warning that violence was expected to escalate before elections scheduled for January 2005.
But Bush dismissed a gloomy CIA forecast for Iraq by saying the agency was "just guessing" when it warned of a possible civil war or, in the best scenario, could cling to tenuous stability.
The president criticised Kerry for
being fickle on security issues
With just six weeks to the 2 November election, Bush took aim at Democratic White House hopeful John Kerry, who accuses him of "colossal failures of judgment" that have wrought a "crisis of historic proportions" in Iraq.
"My opponent has taken so many different positions on Iraq that his statements are hardly credible at all," said the president, who has frequently charged that Kerry is fickle on crucial national security issues.
In his speech, Bush urged UN members to heed two recent Security Council resolutions, including one in June that endorsed the interim Iraqi government and a multinational force to keep order.
"The UN and its member nations must respond to Prime Minister Allawi's request and do more to help build an Iraq that is secure, democratic, federal and free," said Bush, whose address drew applause only when it ended.
Bush said Iraqi interim PM Allawi's
plea for help must be heeded
Bush said democracy in Iraq would spread across the Middle East and, in a rare rebuke, urged staunch US ally Israel to freeze settlements in the West Bank and Gaza and end the "daily humiliation" of Palestinians.
Bush offered no new strategies to overcome violence in Iraq and made no explicit mention of the failure to find arsenals of weapons of mass destruction or evidence of close Iraqi ties to al-Qaida - his two main justifications for launching the war without UN approval.
Instead, the US president tipped his hat to the roughly 40 nations that backed the invasion, which he said had "enforced the just demands of the world" that Saddam Hussein disarm.
"My nation is grateful to the soldiers of many nations who have helped to deliver the Iraqi people from an outlaw dictator," said Bush, who had derided the United Nations as a "debating society" for failing to endorse the invasion.
"All civilised nations are in this struggle together, and all must fight the murderers"
US President George Bush
The president linked the unrest in Iraq to "extremist violence" in Spain, Israel and Turkey, as well as the grisly hostage crisis at a Russian school.
And he blamed "a terrorist group associated with al-Qaida" for much of the violence in Iraq, including the beheadings of captives.
"These acts violate the standards of justice in all cultures and the principles of all religions. All civilised nations are in this struggle together, and all must fight the murderers," said Bush.