Debate over what to do about Iraq continues to rage at the White House and on Capitol Hill, where lawmakers heard from analysts for a second day about the possible effects that would occur if the United States attacked the rogue nation.

Asked what President Bush would tell Jordan's King Abdullah during their talks Thursday on Mideast peace and the Iraq question, Bush replied: "The policy of my government, our government, of this administration is regime change, for a reason. Saddam Hussein is a man who poisons his own people, who threatens his neighbors, who develops weapons of mass destruction."

Abdullah has long opposed military action against Iraq, and was in town to tell the president that there would be little support for an invasion.

Civilian and military planners are at odds over Iraq -- not about whether regime change is necessary, but how to go about achieving it.

Civilian planners are calling for smaller troop deployments in a lightning air and ground strike. Some in the uniformed services support a more cautious and thorough approach involving tens of thousands of troops, according to a report in Thursday's Washington Post.

At the same time, Congress is holding a second day of hearings on the issue of what to do about a post-Saddam Iraq and whether a U.S. invasion could destabilize the region and require a long-term American military commitment.

"In Iraq we cannot afford to replace a despot with chaos. The long-suffering Iraqi people need to know a regime change would benefit them. So do Iraq's neighbors, and the American people will want that assurance as well," said Sen. Joseph Biden, D-Del., chairman of the Senate Foreign Relations Committee.

Experts including former Defense Secretary Caspar Weinberger and former National Security Adviser Sandy Berger were expected to testify.

On Wednesday, witnesses told the panel that the United States likely would have to spend billions of dollars to keep Iraq stable and soldiers may have to be dispatched to the Persian Gulf region for years.

But they agreed that Saddam should be stripped of weapons-making capabilities, especially since he would be willing to use weapons of mass destruction if his own survival were at stake.

Meanwhile, Iraqi media reported Thursday that Saddam's air force chief told the Iraqi leader that his forces were ready to fight and win if the United States invades.

While Iraq's forces are estimated to be only about 40 to 45 percent of what they were in 1991 when the United States went to war to protect neighboring Kuwait, and would likely drop their defense quickly if challenged, analysts said uniting the disparate opposition groups into a unified government would be difficult.

"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.

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 the leadership of Arab states friendly to the United States.

Secretary of State Colin Powell told Japan's foreign minister Thursday that no decision has been made on what action to take against Iraq, a Japanese official said on condition of anonymity. Powell and Yoriko Kawaguchi met on the sidelines of an Asian security forum in Brunei.

Biden said he did not ask Bush administration officials to testify to avoid interfering with their internal debate on Iraq, but expects to call them for a future hearing. Lawmakers want to be sure the administration seeks Congress' approval before it launches any military campaign.

The Associated Press contributed to this report.