An American arms inspector for the United Nations who quit in protest over U.S. policy toward Iraq says the United States lacked the will to use force against Saddam Hussein and that the Iraqi leader successfully called Washington's bluff.

"It has to be a credible force in order for Saddam to flinch, and I think the Iraqis just called the bluff," Scott Ritter said Sunday on ABC's "This Week."Bill Richardson, U.S. ambassador to the United Nations, denied any weakening of U.S. resolve, saying U.S. forces were "ready to strike if the president decides that."

"Now, Scott Ritter is a good man," Richardson told CNN's "Late Edition." But he contended the record showed the United States has been the strongest supporter of the U.N. weapons inspectors, saying: "We have Iraq contained. There are huge sanctions on Iraq. Iraq is becoming isolated in the U.N. Security Council. So, our policy has yielded results."

Ritter contended that the Clinton administration intervened several times to delay or stop inspections to avoid another showdown with Iraq. "I believe the United States does not want such confrontation because it believes it cannot muster the support for such confrontation," he said.

The United States had very little support last February when it geared up to attack Iraq over Saddam's refusal to allow inspections to go forward. That crisis was averted when Saddam backed down, and Richardson said the Iraqi leader will not be allowed to goad the United States into another crisis.

Richardson said the administration does discuss "timing and tactics" with arms inspector chief Richard Butler and other U.N. officials but that the final decision on proceeding with inspections is up to Butler.

Butler insisted last week, following Ritter's resignation, that the Security Council's will to disarm Iraq is unshaken. He said he was satisfied with the support he has received from the council since Iraq froze cooperation with inspectors on Aug. 5.

Ritter said he had resigned to bring what he called the "failure" of U.S. and U.N. policy "into the public eye."

"There is an illusion of arms control taking place," he said. "Right now we are not doing meaningful inspections in Iraq, and if people do not change course, the end result will be that Iraq will be able to retain these capabilities."

The Senate was returning from its summer recess today, and Republican leaders said they will look into Ritter's charges and the administration's approach to Iraq.

"I think the American people have been seriously misled," Senate Budget Committee Chairman Pete Domenici, R-N.M., said on ABC.

"We're over there saying we're holding their feet to the fire, we are sending our men and women over there, we are spending a lot of our tax dollars, and behind the scenes, if this is happening, then I think the administration has to be held accountable," he said.