The mercenaries, known as "mercs" in Iraq and Afghanistan, are generally paid far more than their regular-army equivalent while being far less to not at all accountable either to local laws or to regular-army codes of conduct. In late 2008, the United States signed an agreement with Iraq regulating the status of U.S. troops and mercenaries under contract to U.S. firms or the military on Iraqi soil. Mercenaries immunity from Iraqi law was abolished.
It isn't known how many mercenaries served in Iraq overall or at any given time. Estimates have ranged from 25,000 to 75,000. Between 2003 and 2008, the U.S. government paid a total of $85 billion for private military services, according to Steve Fainaru, a Washington Post reporter who covered mercenaries in Iraq and wrote Big Boy Rules: America's Mercenaries Fighting in Iraq (DaCapo, 2008).
The largest mercenary companies operating in Iraq have included:
- Blackwater Worldwide of Moyock, N.C.
- DynCorp of Falls Church, Va.
- Triple Canopy Inc. of Herndon, Va.


