In a broad-ranging foreign policy speech, Republican John McCain on Wednesday called anew for the United States to work more collegially with democratic allies and live up to its duties as a world leader, drawing a sharp contrast to the past eight years under President Bush.

"Our great power does not mean we can do whatever we want whenever we want, nor should we assume we have all the wisdom and knowledge necessary to succeed," the likely presidential nominee told the Los Angeles World Affairs Council.

McCain's speech was intended to signal that he would end an era of what critics have called Bush's cowboy diplomacy, though McCain never mentioned Bush's name.

In Iraq, McCain said, the U.S. goal should be to "win the hearts and minds of the vast majority of moderate Muslims who do not want their future controlled by a minority of violent extremists." Withdrawing from Iraq, as his Democratic rivals advocate, he said, "would be an unconscionable act of betrayal" that could subject the Iraqi people to violence, ethnic cleansing and possibly genocide.

McCain also said:

• Radical Islamic terrorism is "the transcendent challenge of our time."

• The Guantanamo Bay detention center should be closed.

• Russia should be expelled from the G-8 to make the group once again "a club of leading market democracies."

• A cap-and-trade system should serve as a successor to the environmental pact known as the Kyoto Protocol.

Democratic National Committee chairman Howard Dean said McCain failed to offer any meaningful new policies.

"John McCain's empty rhetoric today can't change the fact that he has steadfastly stood with President Bush from Day One and is now talking about keeping our troops in Iraq for 100 years," Dean said in a statement. "His new appreciation for diplomacy has no credibility after he mimicked President Bush's misleading case for a unilateral war of choice when it mattered most."

EVENTS CANCELED

The Rev. Jeremiah Wright, presidential candidate Barack Obama's controversial former pastor, canceled plans to receive an award this weekend at a Dallas summit on black churches.

Wright also has canceled plans to speak at three services in a Houston church Sunday. He canceled plans Tuesday to speak at a church in Tampa, Fla.

The Rev. Marcus Cosby, pastor at Houston's Wheeler Avenue Baptist Church, said safety concerns had prompted Wright's decision.

Last week, Obama sharply condemned some of Wright's remarks. But the Illinois senator refused to repudiate Wright.

NOT BACKING DOWN

Former President Bill Clinton said his wife won't back down from a fight with her rival Barack Obama no matter how contentious the Democratic presidential race becomes. In Parkersburg, W.Va., Clinton told several hundred supporters that the division between Hillary Rodham Clinton and Obama is nothing to be concerned about, and if politicians don't want to get "beat up," they shouldn't run.

NEW PARTY FOR GRAVEL

Long-shot candidate Mike Gravel, 77, is leaving the Democratic Party to continue his presidential bid with the Libertarian Party. The former senator from Alaska said in an e-mail that the Democratic Party "no longer represents my vision for our great country."

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