Interviewed on the CBS News Early Show, Woolsey added that Saddam is "working hard" to obtain nuclear weapons to go along with Iraq's chemical stockpiles.
The Senate holds a second day of hearings Thursday on the question of going to war with Iraq, while President Bush discussed the issue with Jordan's king.
A former top U.N. weapons inspector told a U.S. Senate committee on Wednesday Iraq's weapons program was an active threat but the international community should give Saddam Hussein another chance to let inspectors in "before taking other measures."
Analysts warn that if Saddam is overthrown, the United States may have to spend billions of dollars to keep Iraq stable. Soldiers may have to be dispatched to the Gulf for years, and U.S. allies could be overthrown, analysts say.
The Senate Foreign Relations Committee is concluding two days of hearings on Iraq with a look Thursday at what's likely to happen if the United States succeeds in driving Saddam from power.
"It would be a tragedy if we removed a tyrant in Iraq, only to leave chaos in his wake," Chairman Joseph Biden, a Delaware Democrat, said Wednesday.
The hearings come as the Pentagon is drawing up new plans for the possible war against Iraq, reports CBS News Capitol Hill Correspondent Bob Fuss, and Democrats, including Senate Majority Leader Tom Daschle, insist Congress needs a say.
"It would be a big mistake for the administration to act without Congress and without its involvement," the South Dakota Democrat said. "There has to be a debate, there has to be a good discussion, there has to be some opportunity for the people to be heard."
Republican counterpart Trent Lott of Mississippi scoffs at the idea of Congress voting to authorize a war.
"'By the way, here's the way we're coming, but before that, we'll have a huge debate so you'll know full well what's going on.' Give me a break!" he told reporters. "What you're talking about there is just a blatant political move that's not helpful."
President Bush Thursday told Jordan's King Abdullah Thursday his policy still calls for a regime change in Iraq, reports CBS News Correspondent Mark Knoller. Abdullah has criticized talk of war with Baghdad, but at the White House, he merely said there are many areas of agreement.
The Jordanian monarch faces the challenge of being an American ally and leader of country with many Palestinians who support Saddam Hussein.
The Bush administration says there is no decision on a war with Iraq but the Pentagon is busy drawing up new battle plans.
Defense Secretary Donald Rumsfeld, who has been reluctant to discuss Iraq, stressed to reporters on Wednesday that "the president has not made any decisions with respect to military activity relating to Iraq or anywhere else."
"The more the question is asked, the more it is discussed in the press, the greater the confusion that exists in the world and the Congress on the issue," he said.
Several experts at the hearing Wednesday, including former U.N. weapons inspector Richard Butler, doubted Saddam would make sufficient conciliatory gestures to avoid an American attack.
But in the absence of a "smoking gun" — hard evidence of an Iraqi intention to use weapons of mass destruction or pass them on to international terrorist groups — that approach could be used to justify eventual invasion, they said.
Butler headed the U.N. inspection agency set up to supervise the dismantling of Saddam's weapons after the 1991 Gulf War, but inspectors left the country in 1998. He said it was important to try again to get inspections resumed.
"I think we've got to go a little further way if for no other reason than to make clear to the world that we went the full distance to get the law obeyed and arms control restored before taking other measures," Butler said.
But Khidhir Hamza, an Iraqi nuclear physicist who defected in 1994, said it is unlikely inspectors could uncover hidden weapons-development programs.
"With no large, easily distinguishable nuclear sites and little or no human intelligence, it is difficult to see how any measure short of a regime change will be effective," he said.
A series of Iraq analysts generally agreed that Iraq must be stopped from developing biological, chemical or even nuclear weapons.
But there were differences about whether a U.S. military invasion was the solution — at least right now.
Morton Halperin of the Council on Foreign Relations suggested tightening the economic embargo against Iraq and providing economic assistance to states along its border to discourage smuggling.
Retired Air Force Lt. Gen. Thomas McInerney said a massive air, land and sea assault could dominate Iraq's military in 72 hours. He said Iraqi forces have been weakened since the 1991 Gulf war and most of the Iraqi army doesn't support Saddam.
But others warned that, if attacked, Saddam would likely unleash his weapons of mass destruction because he'd have nothing to lose with his own survival in jeopardy.
Even if the U.S. forces quickly topple Saddam — something other analysts said shouldn't be taken for granted — the United States will face the difficulty of trying to unite rival groups in Iraq into a stable, friendly government.
Analysts said that could require U.S. forces to remain in Iraq for years at a cost of billions of dollars. Any invasion and long-term U.S. presence would be widely unpopular in the Arab world, which could threaten then leadership of Arab states friendly to the United States.
"Even if the Iraqi people have a happy outcome, I believe that most people in the region will see this as American imperialism," said Shibley Telhami of the University of Maryland.