Updated

Democrat Barack Obama called for ridding the world of nuclear weapons Tuesday and offered his early opposition to the Iraq war as evidence of sound judgment that trumps his lack of Washington experience.

Obama argued that U.S. policy is still focused on the defunct Soviet Union instead of combatting the nuclear threat from rogue nations and terrorists. The United States shouldn't unilaterally disarm, he said, but it must work with other nations to phase out weapons and control atomic material.

"Here's what I'll say as president: 'America seeks a world in which there are no nuclear weapons,"' Obama said.

"The best way to keep America safe is not to threaten terrorists with nuclear weapons — it's to keep nuclear weapons and nuclear materials away from terrorists," the Illinois senator said. Aides said the process Obama envisions would take many years, not just a single presidency.

The Republican National Committee criticized the proposal as unsafe and an example of Obama "playing to the fringe elements of his party." But the concept has the backing of at least two former Republican secretaries of state, Henry Kissinger and George Shultz.

Obama's address marked the fifth anniversary of an anti-war rally where he announced his opposition to invading Iraq. He predicted then that the United States would get bogged down in an unending war that would inflame world anger.

Later in Iowa, Obama turned much of his attack on President Bush whose politics, he said, has left the country more divided, distrusted, in debt and with "an open-ended occupation of a foreign country."

"We've paid a heavy price for having a president whose priority is expanding his own power," declared Obama to a crowded convention center in downtown Des Moines.

"The Constitution is treated like a nuisance to be avoided as opposed to the foundation of our liberty. We get shifting spin, secret task forces, secret budgeting, slanting intelligence and shameful smearing of people who speak out against the president's policies," he said

Obama was an Illinois legislator contemplating a run for the U.S. Senate when Congress voted in October 2002 to give President Bush the authority to use military force to oust Iraqi leader Saddam Hussein.

In his speeches Tuesday, Obama criticized not only Bush, but the media and especially Congress, arguing that they failed the nation in the rush to war.

"Let's be clear: Without that vote, there would be no war," Obama said, taking a swipe at his Democratic rivals who were in the Senate and voted for the war — Hillary Rodham Clinton, John Edwards, Chris Dodd and Joe Biden — but never mentioning them by name.

"Some seek to rewrite history. They argue that they weren't really voting for war, they were voting for inspectors, or for diplomacy. But the Congress, the administration, the media and the American people all understood what we were debating in the fall of 2002," Obama said. "And we need to ask those who voted for the war: How can you give the president a blank check and then act surprised when he cashes it?"

Obama said Congress had failed U.S. citizens on Iraq, despite a law passed after Vietnam that was meant to serve as a check on the president's ability to take the country to war.

"No law can force a Congress to stand up to the president. No law can make senators read the intelligence that showed the president was overstating the case for war. No law can give Congress a backbone," he said.

Obama cites his early opposition to war as evidence that he has the judgment to be president despite arriving in Washington less than three years ago. He plans at least 10 stops in Iowa this week where he will try to drive home that idea.

But he has sometimes acknowledged the Iraq vote wasn't a simple issue. In 2004, he wouldn't criticize presidential nominee John Kerry for the vote, saying, "What would I have done? I don't know."

His message was blunted Tuesday by Clinton's announcement that she had bested Obama's campaign fundraising this summer by bringing in $22 million for the primary election season.

Obama's comments on Iraq and nuclear weapons were part of a broader call for an aggressive new approach to international affairs. As president, Obama said, he would:

—Personally conduct negotiations with other nations, including hostile countries.

—Deliver an annual "state of the world" speech to assess the country's foreign policy concerns.

—Give the director of national intelligence a fixed term of office, so he could not be replaced by the president for political reasons.

—Fight global poverty and double foreign assistance to $50 billion a year.

A spokeswoman for Edwards pointed out that the former North Carolina senator called for the elimination of nuclear weapons months ago.

"If you need any more proof that John Edwards is shaping the race for the Democratic nomination, you don't need to look any further than Senator Obama, who has followed Edwards' lead on heath care, poverty, and today, eliminating nuclear weapons. Next thing you know, he'll be rooting for the Tar Heels," said spokeswoman Colleen Murray.