President Bush said Friday that progress has been made in stabilizing Iraq in the year since he declared an end to major combat, but his Democratic challenger insisted the United States has not succeeded in its mission and now faces a "moment of truth" in the conflict.

"This anniversary is not a time to shout. It is not a time for blame," presidential candidate John Kerry (search) said at Westminster College (search). "It is a time for a new direction in Iraq and for America to work together so that once again this nation leads in a way that brings the world to us and with us in our efforts."

Bush landed aboard the USS Abraham Lincoln (search) on May 1, 2003, to announce that major combat operations were over in Iraq after just six weeks of fighting. Critics repeatedly cited the declaration, made as a banner reading "Mission Accomplished" hung above the flight deck, after U.S. casualties continued to mount.

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The president defended his speech on Friday, telling reporters in the Rose Garden of the White House that "we're making progress, you bet" and noting he had warned at the time that "there was still difficult work ahead."

"A year ago I did give the speech from the carrier saying we had achieved an important objective, accomplished a mission, which was the removal of Saddam Hussein (search)," Bush said. "As a result, there are no longer torture chambers or mass graves or rape rooms in Iraq."

At least 738 U.S. servicemen and women have died in Iraq, nearly 600 since Bush's declaration. More than 120 have died by hostile fire in April, the war's deadliest month.

"This moment in Iraq is a moment of truth," Kerry said. "Not just for this administration, the country, the Iraqi people, but for the world. This may be our last chance to get this right. We need to put pride aside to build a stable Iraq. We must reclaim our country's standing in the world by doing what has kept America safe and made it more secure before — leading in a way that brings others to us so that we are respected, not simply feared, around the globe."

Kerry's speech at Westminster College came four days after Vice President Dick Cheney (search) denounced his leadership on the same campus. "The senator from Massachusetts has given us ample grounds to doubt the judgment and the attitude he brings to bear on vital issues of national security," Cheney said during his visit Monday.

Cheney repeated many of the criticisms he had leveled at Kerry in a California speech weeks earlier, prompting Westminster President Fletcher Lamkin (search) to complain of "Kerry-bashing" by the vice president. Kerry accepted Lamkin's invitation to offer a rebuttal at the campus, the site of British statesman Winston Churchill's "Iron Curtain" address in 1946.

Citing the "Mission Accomplished" banner, Kerry said, "I don't think there's anyone in this room today or 6,000 miles away who doesn't wish that those words had been true ... but we've seen the news. We've seen the pictures. And we know we are living through days of great danger."

Kerry has chastised the president for failing to get more international assistance. He has said that other nations have an interest in a peaceful Iraq, so the United States should reach out to them to share the cost.

In his Westminster speech, Kerry called for NATO to make Iraq part of its global mission as a security organization, for the U.N. Security Council to authorize a high commissioner for governance and reconstruction, and for a massive effort to build an Iraq security force.

"Will all this be difficult to achieve? Yes," Kerry said. "Is there a guarantee of success? No. In light of all the mistakes that have been made, no one can say that success is certain, but I can say that if we do not try this, failure is all too likely."

Kerry also invoked the memory of President Truman, a native of this battleground state in the 2004 election.

"President Truman could have used America's power as an excuse to go it alone in the world," Kerry said. "Instead, he joined with the leaders of many nations to create institutions like NATO and other alliances to preserve peace, spur economic progress and address global problems."

Kerry's response was an opportunity for him to highlight what could become one of Bush's biggest vulnerabilities in the election — recent polls show public doubts are growing about Iraq and the president's handling of the war. Yet this has not transferred into support for Kerry.

Although Kerry avoided partisan sniping with Republicans, earlier this week he was clearly miffed by Cheney's accusations. On Thursday, he accused Republicans of distorting his record through "scare-tactic politics."

"To suggest to Americans that I, who have already defended my country, wouldn't defend it today is an insult to the intelligence of Americans," he told donors gathered at Philadelphia City Hall.