The wars in Iraq and Afghanistan could cost American taxpayers $1 trillion, according to the most recent projections made by the nonpartisan Congressional Budget Office.

Download Full CBO Report

Robert A. Sunshine, CBO assistant director for budget analysis, testified about the figures befopre the House Budget Committee on Tuesday.

His office researched the costs of the wars in two different scenarios. In the first scenario, personnel deployed on the ground for the war on terrorism would be reduced from the 2007 average of about 210,000 to 30,000 by the beginning of 2010 and then remain at that level through 2017, Sunshine said.

Under those conditions, the cost would range from about $481 billion to $603 billion.

In the second scenario, the number of personnel deployed would decline more gradually, from an average of 210,000 in 2007 to 75,000 by the start of 2013 and then remain at that level through 2017, he said.

In that case, the wars could cost taxpayers $924 billion to $1,010 billion.

Sunshine also said that, since Sept. 2001, Congress has appropriated $602 billion for military operations and other activities related to Iraq, Afghanistan, and the war on terrorism in general.

The report was issued as the White House and Pentagon were set to make a $141 billion budget request from Congress for military operations in Iraq and Afghanistan for the budget year.

Part of the package includes about $5.3 billion for bomb-resistant vehicles called MRAPS.

Deputy Secretary of Defense Gordon England said the vehicles have special V-shaped undercarriages that can deflect roadside bomb blasts and better protect troops.

England told the House Budget Committee that other costs, especially President George W. Bush's ongoing strategy of increased troop levels in Baghdad and Anbar province, will require additional funding. But England said he couldn't yet pinpoint the exact amount needed.

Meanwhile, a senior Army commander told U.S. allies in Kuwait on Wednesday that when the U.S. exits the region, the redeployment will be methodical.

"Just as we are very deliberate and methodical going to war -- and the United States does that very well -- we also need to be very deliberate and methodical coming out," said Army Lt. Gen. R. Steven Whitcomb, commander of 3rd U.S. Army.

Whitcombe would have overal responsibility for the logistics of pulling the U.S. military out of the region when the time comes.

He said the way the United States redeploys its troops and equipment will send "a strategic message, not only to our friends here in the region, but to our adversaries or potential adversaries (who will) watch very carefully."

"So we can't just come down helter-skelter," he said. "It is the strategic communications aspect of not just driving things down and parking it here for three or four months. (That) is not the way to do it. We need to be deliberate, and we have that capacity to be deliberate."

Whitcombe was traveling with Secretary of State Condoleezza Rice and Secretary of Defense Robert Gates.