Armies have always had civilians along, to perform support functions.
The historical term is "camp followers." In Iraq, the American army has about
eight civilians for every ten troops. In times past, the ratio of civilians to
soldiers was often much higher, like eight civilians for every one soldier.
Only the most disciplined armies (like the ancient Romans at their peak), kept
the ratio closer to one to one. But when conscript armies became common in the
19th century, it was suddenly cheaper to replace many of those civilians with
conscripts (who were paid a nominal wage.) Now that armies are going
all-volunteer, it's gone back to the old days, where it's cheaper to have
civilians for a lot of support jobs.
a lot safer to be a contractor in Iraq, than a soldier. Only 769 contractors
have died there, which means you are three times more likely to get killed if
you are in uniform. Most contractors works in the well defended bases, and most
of the contractor casualties are among those (about a quarter of the total) who
do security or transportation jobs. But even those have a lower casualty rate
than the combat troops. For the really dangerous work, the troops are used. But
working in a combat zone is still dangerous, no matter what your work clothes