If U.S. forces were to leave Iraq before it was stabilized, it would create "instant instability" in the Middle East, including in Saudi Arabia and possibly Iran, the military's top general said Friday.

Gen. Richard Myers (search), chairman of the Joint Chiefs of Staff, told a Pentagon news conference that the United States must maintain its will to prevail in Iraq, where the terrorist element of the insurgency is led by Abu Musab al-Zarqawi (search) of Jordan, the second most-wanted terrorist on the U.S. list after Al Qaeda leader Usama bin Laden.

"If the Zarqawis of the world were allowed to be successful in Iraq in their view, and that would be the start of the caliphate that they envision, the stakes would be huge for the region," Myers said. His use of the term caliphate referred to a single Islamic government run by religious extremists.

"You talk about instability. It would be instant instability in that region, in Saudi Arabia, on down the Gulf states, perhaps Iran, Syria, Turkey," Myers added. "Just economically, it would be instability of the sort that would affect the globe, and then they would keep pressing on, they would continue their movement and it would involve, in my view it would involve terrorist incidents certainly that would expand."

"They would be buoyed by this victory," he added.

Myers appeared before reporters to discuss his recent 10-day trip around the world to visit U.S. troops in Europe, the Middle East and Asia. He said he found that troop morale was high, including in Iraq and Afghanistan.

Myers is stepping down as Joint Chiefs chairman on Sept. 30, to be succeeded by Gen. Peter Pace (search).

Earlier on Friday, an Army commander in Iraq predicted that insurgent violence will increase in the Sunni-dominated areas he commands north of Baghdad, but he also said there is a growing confidence among Iraqis that the insurgents will fail to stop planned elections in October and December.

Army Maj. Gen. Joseph J. Taluto, commander of the 22,000-soldier Task Force Liberty, also said that while his election security plan does not require any additional U.S. troops, he could use extra help if it were offered by Gen. George Casey, the top overall commander in Iraq, who is assessing election security needs.

Earlier this week the Pentagon announced that 1,500 soldiers from the 82nd Airborne Division (search) at Fort Bragg, N.C., would be sent to Iraq for election security duty, but it did not say where in Iraq they would operate.

"If my boss offered up additional forces I would use them in certain places, but they are not 100 percent required," Taluto said in a two-way video link with reporters at the Pentagon. He spoke from his headquarters at Tikrit, the Tigris River city that is the home town of former Iraqi President Saddam Hussein.

Iraqis are to vote in mid-October in a national referendum on a constitution, and if that is approved it would form the basis for the election of a new government in mid-December. That political process is widely viewed as a key to stabilizing the country and permitting U.S. troops to begin withdrawing.

Taluto described the insurgency in north-central Iraq, where his troops are operating along with five brigades of U.S.-trained Iraqi soldiers, as resilient but not increasing the volume of its attacks in recent weeks.

"We expect that the enemies will increase their attacks, particularly as we run up to the referendum," he said. "The divergent groups all have their own strategies and they select a time for these attacks. But they go up and then we'll have a week or two where the attacks will go down, and they seem to rearm themselves and then re- attack."

Asked why the U.S. military has been unable thus far to defeat the insurgents, Taluto said progress is being made and it is not widely recognized that U.S. troops stop many attacks before they can be executed. On the other hand, he said, it also is true that the insurgents have become part of the fabric of Iraqi life.

"They are intrinsic, and so it seems like they can act with impunity," Taluto said. "And then they do escalate their activities, so they surge and so on and so forth."