"Under international humanitarian law, military commanders must prevent and where necessary suppress serious violations involving the local population under their control or subject to their authority. Furthermore, occupying forces have an immediate duty to take all feasible steps to prevent acts of violent reprisal.
The responsibility for protecting civilians extends to the conduct of any local Iraqi armed groups acting under authority of or in conjunction with U.S. forces. That duty exists for the benefit of individuals allied with the Iraqi government who have laid down their arms as well as opponents of the government. Human Rights Watch has outlined these duties previously in a policy paper (
http://www.hrw.org/backgrounder/arms/iraq0202003.htm) and a letter to U.S. Secretary of State Colin Powell and other U.S. allies (
http://www.hrw.org/press/2003/03/us031903ltr.htm). "