Secretary of State Colin Powell (search) acknowledged Thursday that he had seen no "smoking gun, concrete evidence" of ties between Saddam Hussein and the Al Qaeda terror network, but insisted that Iraq had had dangerous weapons and needed to be disarmed by force.

At a State Department news conference, Powell disagreed with a private think tank report that maintained Iraq had not been an imminent threat to the United States. And the secretary defended the case he had made last February before the United Nations for a U.S.-led war to force Saddam from power.

"My presentation ... made it clear that we had seen some links and connections to terrorist organizations over time," Powell said. "I have not seen smoking gun, concrete evidence about the connection, but I think the possibility of such connections did exist and it was prudent to consider them at the time that we did."

Three experts at the Carnegie Endowment for International Peace (search) said in a report Thursday that the Bush administration systematically misrepresented a weapons threat from Iraq, and U.S. strategy should be revised to eliminate the policy of unilateral preventive war.

"It is unlikely that Iraq could have destroyed, hidden or sent out of the country the hundreds of tons of chemical and biological weapons, dozens of Scud missiles and facilities engaged in the ongoing production of chemical and biological weapons that officials claimed were present without the United States detecting some sign of this activity," said the report by Jessica T. Mathews, Joseph Cirincione and George Perkovich.

Powell noted that Saddam had and used destructive weapons in the late 1980s, then refused for a decade to assure the world he'd gotten rid of them.

"In terms of intention, he always had it," Powell said. Of Carnegie's finding that Iraq posed no imminent threat, Powell said, "They did not say it wasn't there."

Iraq's nuclear program had been dismantled and there was no convincing evidence it was being revived, the report said.

And the U.S.-led war on Iraq in 1991 combined with U.N. sanctions and inspections effectively destroyed Iraq's ability to produce chemical weapons on a large scale, it said.

The real threat was posed by what Iraq might have been able to do in the future, such as starting production of biological weapons quickly in the event of war, Carnegie said.

Also, Iraq apparently was expanding its capability to build missiles beyond the range permitted by the U.N. Security Council (search), the report said.

Years of U.N. inspections to determine whether Saddam was harboring weapons of mass destruction were working well, and the United States should set up jointly with the United Nations a permanent system to guard against the spread of dangerous technology, the report said.

It recommended that consideration be given to making the job of CIA director a career post instead of a political appointment.

Mathews is president, Cirincione is director of the proliferation project, and Perkovich is vice president for studies at Carnegie, an independent research group.

Meanwhile, an unscientific State Department survey released this week showed most residents in five Iraqi cities believed attacks against Iraqi civilians, police and international organizations are more harmful than helpful for Iraq's future. About a third of Iraqis said attacks against the U.S. forces are helpful.

The survey also showed about two-thirds of those surveyed say the attacks emphasize the need for the continued presence of coalition forces in Iraq. A majority thought that troops should depart after a permanent government is elected by the Iraqi people.