Law and policy govern the actions of the U.S. forces in all military operations, including counterinsurgency. For U.S. forces to conduct operations, a legal basis must exist. This legal basis profoundly influences many aspects of the operation. It affects the rules of engagement, how U.S. forces organize and train foreign forces, the authority to spend funds to benefit the host nation, and the authority of U.S. forces to detain and interrogate. Under the Constitution, the President is commander in chief of the U.S. forces. Therefore, orders issued by the President or the Secretary of Defense to a combatant commander provide the starting point in determining the legal basis. This appendix summarizes some of the laws and policies that bear upon U.S. military operations in support of foreign counterinsurgencies. Laws are legislation passed by Congress and signed into law by the President, as well as treaties to which the United States is party. Policies are executive orders, departmental directives and regulations, and other authoritative statements issued by government officials. No summary provided here can replace a consultation with the unit's supporting staff judge advocate.
D-1. U.S. forces have limited authority to provide assistance to foreign governments. For foreign internal defense, U.S. forces may be authorized to make limited contributions. Assistance to police by U.S. forces is