A new report says the United States has spent about $100 billion on private contractors to support operations in Iraq since the 2003 invasion to oust Saddam Hussein.  VOA's Michael Bowman reports from Washington.

At the height of last year's military surge in Iraq, the United States had roughly 168,000 troops deployed in the country.  But America's armed forces have been outnumbered by what some see as a private army funded by the federal government: contractors that provide a wide array of services, from security operations to rebuilding projects to logistical support.

Peter Orszag heads the Congressional Budget Office, which issued a report on the costs of private contractors in Iraq.

"The federal government has awarded $85 billion in contracts for work in [the] Iraq theater through 2007.  If you included this year, the total would exceed $100 billion: roughly one of every $5 for the cost of the war in Iraq," he said.

Orszag says the use of private contractors in U.S. military engagements is not new. What is new, however, is the extent of the reliance on private firms. The Iraq war marks the first time in which the number of private personnel has equaled or exceeded the number of military personnel. By contrast, the CBO report notes that, during World War II, military personnel outnumbered private contractors by a ratio of seven-to-one.

The CBO says most private contracts for Iraq have been awarded through the Department of Defense and the State Department.  According to the report, the yearly cost of maintaining a single private contractor in Iraq can approach half a million dollars - far exceeding the annual pay of even the most senior military commanders.

But the CBO estimates that, when combat pay, benefits, and troop rotations are factored in, the cost of a private contractor is roughly equivalent to that of a soldier performing the same function.

Pentagon officials openly admit that, even with extensive use of private contractors, America's lengthy engagement in Iraq has placed heavy burdens on the military.  Peter Orszag says, without the contractors, the strain would be even more severe.

"We are really running our military at a much harder rate without the kind of rest and retraining that the military itself says is necessary. Given the level of operations we are engaged in, were it not for the contractors, we would presumably be running an even less-sustainable pace of activity for military personnel," he said.

Orszag says one advantage of using private contractors is the ability to rapidly terminate funding when services are no longer required.  By contrast, military personnel enlist for years at a time and remain on the payroll for the duration of their service.  But the CBO director also noted that private contractors have come under scrutiny for allegations of fraud and abuse in Iraq, and employing them necessitates vigilance and oversight to ensure that funds are not misused.