Sen. John F. Kerry (D-Mass.) charged yesterday that the Bush administration is on a "rush to war" in Iraq that will endanger U.S. alliances and fan anti-Americanism around the world.

At the same time, the Democratic presidential candidate repeated his belief that Saddam Hussein "presents a particularly grievous threat" to the United States because of his long record of dangerous actions in a volatile region. The Iraqi leader could be confronted more effectively, Kerry said, if the White House would "do the hard work" of explaining the threat and of building a coalition to invade Iraq, if that proves necessary.

But he did not go so far as to say the United Nations must approve an invasion. "My support is not contingent" on a new Security Council resolution, Kerry said, "but it would be better."

By embracing the goal of disarming Iraq while sharply criticizing the administration's tactics, Kerry continued his efforts of recent months to steer a middle course when pacifist voices are on the rise in his party.

Among pages of oratory blasting "the Bush administration's blustering unilateralism," Kerry also included a few lines of rebuke for "those who reflexively oppose any U.S. military intervention anywhere."

But during the question period after his speech at Georgetown University, Kerry learned what a fine line he will be walking.

A student assailed him for voting in favor of a congressional resolution last fall authorizing President Bush to use force in Iraq. Kerry, a decorated Vietnam War veteran who returned to lead antiwar protests a generation ago, extolled the "voices of dissent" heard at recent peace demonstrations. But he said those who see no need to enforce U.N. resolutions to disarm Iraq probably should not vote for him.

Kerry is one of six declared candidates for the Democratic nomination in 2004; several others are deciding whether to run. In this speech, he staked out foreign policy ground previously occupied by former vice president Al Gore, whose decision not to seek a rematch with Bush has thrown the race for the Democratic nomination wide open.

In a speech last February in New York, Gore struck most of the same themes Kerry sounded yesterday: the menace of Hussein, the need for cultivating alliances, the importance of U.S. leadership to address global warming and the AIDS crisis in Africa.

In describing the war on terror, the two even shared the same metaphor: that poverty and oppression in the Middle East are the stream supplying the "swamp" of terrorists.

As Kerry put it: "We must drain the swamps of terrorists; but you don't have a prayer of doing so if you leave the poisoned sources to gather and flow again. That means we must help the vast majority people of the greater Middle East build a better future."

Kerry observed that, in a world in which economic advancements are helping to bring countries from Vietnam to Uzbekistan into peaceful coexistence with the West, Middle Eastern countries are lagging.

"A combination of harsh political oppression, economic stagnation, lack of education and opportunity, and rapid population growth has proven simply explosive," he said, and so steps must be taken to increase trade with the Arab world. "The Bush administration has a plan for waging war," he said, "but no plan for winning the peace."

Kerry mocked the administration's dealings with North Korea as "a merry-go-round policy: They got up on their high horse, whooped and hollered, rode around in circles, and ended up right back where they'd started in the first place."

Former Vermont governor Howard Dean, the strongest critic of war in Iraq among the Democratic candidates, welcomed Kerry's speech but said it was not enough.

"I'm thrilled that there is now another Democrat speaking up for Americans who are concerned about the White House's unilateralist foreign policy and the likely war with Iraq," he said. "But I am proud to remain the only elected official running for president who . . . said the [use of force] resolution was wrong."

White House spokesman Scott McClellan dismissed Kerry's speech as an example of Democratic confusion, saying: "It would probably be helpful if the Democratic hopefuls could resolve their differences and develop a coherent foreign policy for their own party. I think the American people know the president has provided strong leadership and clear and consistent views in foreign policy."

At Georgetown University, Sen. John F. Kerry accused Bush of "blustering unilateralism," but conceded that Iraq must be disarmed.