Dave,
Civilians form a very large part of our military force structure. Many reasons cause that to be so. The size of the military is limited to numbers of troops, equipment and the like. In order to have a flexibility to scale up or down, civilian contractors allow for that and are actually very cheap as compared to maintaining large numbers of troops all who require pay, housing, medical/dental care, pensions and the like.
Our military has wisely accepted the proposition that general trades manning can very easily be taken care of by hiring contractors when operational committments require and thus are able to field more combat arms troops and equipment.
Halliburton, the favored spear catcher for critics of those on the left....is just one of many corporations that vie for those contracts. They in turn hire folks on contract rather than as permanent employees. That way they in turn minimize the cost of supplying workers and equipment.
Is there a rip off of the taxpayer in this system? Probably....but what government operation is not a rip off? How many trillion dollars has been spent on welfare and anti-poverty programs in the United States with no visible change in the numbers of poor folk?
I notice of late, that some folks of a particular political view are grandly ignoring the Billion or so dollars worth of fraud, waste, and mis-management in FEMA's Katrina operations. That outcry only comes when someone thinks another party is getting rich at their expense. That shoe changes from foot to foot as you well know.