Defense Secretary Richard B. Cheney, calling Congress "a great debating society," said yesterday he worries that a vigorous congressional debate on the use of troops in the Middle East could "undermine our purposes in the gulf."

As the administration tries to deal with what polls show to be increasing public wariness about U.S. troop deployment in the Middle East and the potential for war, Cheney suggested on NBC's "Meet the Press" that unrestrained debate of the president's goals could "give {Iraqi President} Saddam Hussein comfort . . . because he'll perceive that there's a possibility that the U.S. might, in fact, not continue to remain firm."

However, Cheney acknowledged that, with congressional hearings scheduled for December, to some degree the debate has already begun.

Sens. Richard G. Lugar (R-Ind.) and Joseph R. Biden Jr. (D-Del.), who differ on President Bush's policy in the gulf, said yesterday they agree that the possibility of war should be open for congressional debate.

"It would be tragic, I think, if the Congress voted no; but it would be equally tragic if the Congress never votes -- and then by carping and wailing all the way along the line, we undermine our credibility," Lugar said on ABC's "This Week with David Brinkley."

Cheney, a former House member, said any congressional debate "has to be conducted in a responsible fashion -- you have to be careful about it."

Calling Congress a "great debating society," Cheney said, "I'm not sure it is the kind of place that is capable of making this kind of decision."

Part of the push for congressional debate comes from those who are concerned and confused about Bush's reasons for sharply increasing U.S. troop strength on Iraq's borders.

The administration sought to make its case yesterday not only on several television talk shows but also in an essay in Newsweek magazine by Bush.

In that essay, which the magazine said it requested from the president, Bush said he was explaining his policy decisions concerning what he calls "the first crisis of the post-Cold War era."

In the Newsweek essay -- which charged such abuses by Saddam as shooting children "in front of their parents" -- Bush said he committed troops to the gulf to punish aggression by Saddam, to guard U.S. national security and to protect civilian lives.

But the president also said, "Iraq can never again be in a position to threaten the survival of its neighbors or our vital interests," raising the question of whether a new goal is to disarm Saddam or even oust him.

Asked yesterday whether the reduction of Saddam's huge arsenal of conventional, biological and chemical weapons -- as well as his potential of nuclear weapons -- would be part of any plan, Secretary of State James A. Baker III said on "This Week with David Brinkley" that Saddam's arsenal was "a valid concern" for the president.

"Let's suppose that Saddam Hussein woke up one morning and decided to pull out of Kuwait, and he pulled out of Kuwait but sat there with his disproportionately powerful military machine and his weapons of mass destruction," Baker began. "Clearly, I think, the world, the international community, should be concerned about that, and we would have to give serious consideration to how we approach that problem and what we do about it."

Earlier, Cheney recalled the debate of 1941 in Congress, "when World War II had been underway for two years; Hitler had taken Austria, Czechoslovakia, Poland, Norway, Denmark, the Netherlands, Belgium, France, and was halfway to Moscow.

"And the Congress, in that setting, two months before Pearl Harbor, agreed to extend the selective service system, the draft, for twelve more months, by just one vote," he said. "It's a difficult proposition for Congress to come together" to declare war.

Cheney said Bush had not ruled out seeking a declaration of war from Congress if necessary. But the defense secretary stressed that so far no such decision had been made.