text: Chapter 4
  arrangement with the host country, DOD personnel in foreign countries may be subject to the host country’s
  laws. Commanders ensure that all personnel understand the status of U.S. forces in the area of operations and
  are trained accordingly.
  LEGAL CONSTRAINTS ON MISSIONS
  4-6. U.S. law and regulation play a key role in establishing the parameters by which military forces may
  conduct missions. These parameters tend to constitute constraints on the activities of military units. They
  range from the ROE in combat situations to the authority to spend government funds in furtherance of a
  training or support mission.
  Rules of Engagement
  4-7. Rules of engagement are directives issued by competent military authority that delineate the
  circumstances and limitations under which United States forces will initiate and/or continue combat
  engagement with other forces encountered (JP 3-84). Often these directives are specific to the operation. If
  there are no operation-specific ROE, U.S. forces apply standing ROE. When operating with a multinational
  force, commanders must coordinate the ROE thoroughly and consider the laws of the host country.
  4-8. ROE are a critically important aspect of military operations overseas. ROE contribute directly to
  mission accomplishment, enhance protection, and help ensure compliance with law and policy. While ROE
  are ultimately commanders’ rules to regulate the use of force, judge advocate general personnel nonetheless
  remain involved in ROE drafting, dissemination, interpretation, and training.
  Authority for Security Cooperation and Security Assistance
  4-9. The DOS has the primary responsibility, authority, and funding to conduct foreign assistance on behalf
  of the USG. Foreign assistance encompasses any and all assistance to a foreign nation, including security
  assistance (assistance to the internal police forces and military forces of the foreign nation), development
  assistance (assistance to the foreign government in projects that will assist the development of the foreign
  economy or their political institutions), and humanitarian assistance (direct assistance to the population of a
  foreign nation). The legal authority for DOS to conduct foreign assistance is found in the Foreign Assistance
  Act of 1961 (Public Law 87-195, 22 USC 2151, et. Seq.).
  4-10. All training and equipping of FSF must be specifically authorized. Military and civilian personnel,
  operations, and maintenance appropriations should typically provide only an incidental benefit to those
  security forces. All other weapons, training, equipment, logistic support, supplies, and services provided to
  foreign forces must be paid for with funds appropriated by Congress for that purpose. Moreover, the President
  must give specific authority to the DOD for its role in training and equipping a partner FSF. Absent such a
  directive, the DOD lacks authority to take the lead in assisting a host nation to train and equip its security
  forces.
  4-11. 10 USC funds may be appropriated to the DOD by Congress and managed by combatant commands
  to conduct military-to-military exchanges and traditional commander’s activities. This does not provide the
  authorities for U.S. forces to train or equip partner nation militaries. These programs support cooperative
  military engagement, and fund material support for the following—
  * Humanitarian and civic assistance projects.
  * Participation in exercises.
  * Traditional commander activities, such as conferences, seminars, or military-to-military
  exchanges.
  4-12. Operations and maintenance funds are provided by the combatant command for support of the DOD
  or combatant command security cooperation programs other than security assistance in the country. These
  are DOD funds traditionally provided for the purpose of operating and maintaining U.S. forces such as
  salaries, exercises, training, operations, and overhead costs.