"The CRS study says contractors made up 69 percent of the Pentagon's personnel in Afghanistan last December, a proportion that "apparently represented the highest recorded percentage of contractors used by the Defense Department in any conflict in the history of the United States.""
From the WP article below.
"In the Vietnam war, where U.S. troops were there for a long time, contractors were 16 percent of the force. In the Korean war, civilians were 28 percent of the force. During World War II it was 12 percent, it was 4 percent in World War I, during the U.S. Civil War it was 17 percent, during the Mexican-American War it was 15 percent and during the Revolutionary War, it was 18 percent."
Strategy Page
Up to 56,000 more contractors likely for Afghanistan, congressional agency says
By Walter Pincus
Washington Post Staff Writer
Wednesday, December 16, 2009; A17
The surge of 30,000 U.S. troops into Afghanistan could be accompanied by a surge of up to 56,000 contractors, vastly expanding the presence of personnel from the U.S. private sector in a war zone, according to a study by the Congressional Research Service.
Continued:
The Washington Post