The speech came at a time when Bush's approval ratings in all polls are at their lowest. The same surveys also show diminishing support for a two-year-old war, in which more than 1,700 U.S. troops have been killed. Insurgents also have intensified their attacks in recent months.
But Bush rejected setting a timetable for withdrawing U.S. forces, saying the insurgents would only wait for the final withdrawal to attack an Iraqi government unprepared to defend itself.
Bush said he would keep up his strategy of rooting out insurgents, training and equipping Iraqi defense forces, and helping the Iraqi people make the difficult transition to democracy. He noted that he was speaking on the first anniversary of the transfer of sovereignty from the U.S.-led coalition to the interim Iraqi government.
The president spoke of the pain he feels when he sees television footage of carnage and acknowledged what he called "uneven" progress since the Iraq war began in March 2003. But Bush cited a list of achievements.
"The terrorists, both foreign and Iraqi, failed to stop the transfer of sovereignty," Bush said. "They failed to break our coalition and force a mass withdrawal by our allies. They failed to incite an Iraqi civil war. They failed to prevent free elections. They failed to stop the formation of a democratic Iraqi government that represents all of Iraq's diverse population. And they failed to stop Iraqis from signing up in large numbers with the police forces and the army to defend their new democracy."
As he has many times before, Bush said the war in Iraq is only the latest front in what he calls the "war on terror," which he has been waging since the attacks of 11 September 2001. He said it is better to fight the insurgents in Iraq than in the United States, better to stop them in Iraq then allow them to attack America again.
Bush also invoked 11 September in saying that he was confident that Americans won't back down from a difficult challenge.
"They are trying to shake our will in Iraq just as they tried to shake our will on September 11, 2001," Bush said. "They will fail. The terrorists do not understand America. The American people do not falter under threat and we will not allow our future to be determined by car bombers and assassins."
Bush gave the speech as a direct response to the recent negative polls about his overall performance as president, particularly his conduct of the war, according to Allan Lichtman, a professor of American history at American University in Washington.
"Bush feels he needs somehow to reassure the American people that we are on the right track in Iraq and to try to bolster his own approval ratings," Lichtman told RFE/RL. "His task is a very difficult one because there is a significant segment of public opinion that's truly solidified against him."
In some polls, Lichtman says, that strong anti-Bush sentiment has grown to around 40 percent.
But Lichtman cites one positive figure among the recent surveys: Fully 58 percent agree with Bush that U.S. forces must remain in Iraq until Iraqis can maintain order themselves.
"This is what Bush wants to build on, that still-residual sentiment among a fairly substantial portion of Americans that we don't want to cut and run [abandon the Iraqis] now, that so many Americans have died, so much of our treasure has been spent, that we need to give the war some more time to try to salvage the possibility of a stable and democratic Iraq," Lichtman said.
But Lichtman says Bush's approach to Iraq is beginning to be, in his words, "eerily similar" to that of former presidents Lyndon Johnson and Richard Nixon on the Vietnam War. He concedes that there is no way to predict how the conflict in Iraq will end, and he says he hopes its outcome will be better -- for all sides -- than it was three decades ago in Vietnam.
For the latest news and analysis on Iraq, see RFE/RL's webpage on "The New Iraq".