President Bush appealed to the American public to remember "the lessons of September 11th" and not lose faith in the Iraq war effort despite unremitting violence, declaring in a prime-time address that "the proper response is not retreat."

Surrounding himself with uniformed soldiers and standing before a backdrop emblazoned with American flags, Bush portrayed the two-year-old war in Iraq as the logical extension of a larger struggle that began when hijackers slammed passenger jets into the World Trade Center and the Pentagon in 2001. But with public support wavering in recent polls, Bush spoke in blunt terms about the trauma in Iraq and the desire to bring troops home.

His sober language was a shift in tone from some of the administration's more optimistic statements lately, exemplified when Vice President Cheney asserted that the insurgency is in its "last throes."

But Bush rejected any change in course, ruling out either a deadline for troop withdrawals or an increase in troop levels, as critics from opposite sides of the spectrum have endorsed. Instead, he tried to reassure Americans that the U.S. venture in Iraq has made powerful strides toward establishing a democratic government that ultimately will be able to defeat the insurgency, and he urged Americans not to lose "our heart, our nerve" during "a time of testing."

The address continued a shift in the administration's emphasis as it has justified the Iraq war, beginning with the threat posed by former Iraqi president Saddam Hussein's suspected weapons of mass destruction, continuing to the need to promote democracy in the Middle East and now suggesting a more seamless link to the attacks on American soil.

-- Peter Baker and Dana Milbank

Speaking at Fort Bragg, N.C., about the war in Iraq, President Bush asked that Americans not lose "our heart, our nerve" during "a time of testing."