It will be updated as warranted. Background on the COM Role

"Chief of Mission," or COM, is the title conferred on the principal officer in charge of each U.S. diplomatic mission to a foreign country, foreign territory, or international organization. Usually the term refers to the U.S. ambassadors who lead U.S. embassies abroad, but the term also is used for ambassadors who head other official U.S. missions and to other diplomatic personnel who may step in when no ambassador is present. Appointed by the President, each COM serves as the President's personal representative, leading diplomatic efforts for a particular mission or in the country of assignment under the general supervision of the Secretary of State and with the support of the regional assistant secretary of state. Current Legal Authority of Chiefs of Mission

The authorities and responsibilities of COMs are explained primarily in the Foreign Service Act of 1980, as amended (FSA 1980; P.L. 96-465 ). COM authority is also shaped by executive branch directives, which include executive orders and other presidential directives and State Department regulations, some of which provide more extensive authority than FSA 1980. COM Responsibilities . Pursuant to Section 207(a)(2), the COM is also responsible for keeping " fully and currently informed with respect to all activities and operations of the Government within that country, and shall insure that all Government executive branch employees in that country (except for Voice of America correspondents on official assignment and employees under the command of a United States area military commander) comply fully with all applicable directives of the chief of mission." Common Questions

A number of questions are often raised regarding the scope and exercise of COM authority. Does COM authority extend to Department of Defense (DOD) personnel? Is COM authority in effect in countries where the United States is engaging in hostilities? Who Exercises COM Authority in Countries Without a U.S. Embassy or U.S. Diplomatic Presence? What Is the COM's Authority over Members of Congress, Legislative Branch Employees, and Congressional Foreign Travel? Current Concerns and Possible Options

Congress plays an important role in setting standards for the exercise of COM authority and providing COMs with the resources—training, personnel, monetary—to promote its effective exercise. Conclusion

U.S. ambassadors and others exercising COM authority are by law the cornerstone of U.S. foreign policy coordination in their respective countries. Their jobs are highly complex, demanding a broad knowledge of the U.S. foreign policy toolkit and the ability to oversee the activities and manage the representatives of from many U.S. government entities, which in some embassies number about 40 U.S. departments and agencies.
"Chief of Mission," or COM, is the title conferred on the principal officer in charge of each U.S. diplomatic mission to a foreign country, foreign territory, or international organization. Usually the term refers to the U.S. ambassadors who lead U.S. embassies abroad, but the term also is used for ambassadors who head other official U.S. missions and to other diplomatic personnel who may step in when no ambassador is present. Appointed by the President, each COM serves as the President's personal representative, leading diplomatic efforts for a particular mission or in the country of assignment. U.S. ambassadors and others exercising COM authority are by law the cornerstone of U.S. foreign policy coordination in their respective countries. Their jobs are highly complex, demanding a broad knowledge of the U.S. foreign policy toolkit and the ability to oversee the activities and manage the representatives of many U.S. government entities, with some exceptions for those under military command. Congress plays an important role in setting standards for the exercise of COM authority and providing COMs with the resources—training, personnel, monetary—to promote its effective exercise. A number of recent developments have increased congressional attention to issues associated with the roles and responsibilities of COMs.
The statutory basis for COM authority and responsibilities is the Foreign Service Act of 1980, as amended (FSA 1980; P.L. 96-465), which states that the COM has "full responsibility for the direction, coordination, and supervision of all Government executive branch employees in that countries," with some exceptions; and for keeping "fully and currently informed" about all government activities and operations within that country. COM authority is also conferred by other sources of legal authority, which include executive orders and other presidential directives and State Department regulations, some of which provide more extensive authority than the FSA 1980. The Chief of Mission role in conducting and coordinating diplomacy abroad was also invoked in the first Quadrennial Diplomacy and Development Review (QDDR), released by the State Department in 2010.
The scope and exercise of COM authority, both generally and in specific instances, have been of ongoing interest and concern to Congress. This report summarizes the current legal authority of Chiefs of Mission to include relevant legislation and executive branch directives and regulations. It includes brief discussion of common questions related to COM authority such as:
Does COM authority extend to Department of Defense (DOD) personnel? Who exercises COM authority in countries without a U.S. embassy or diplomatic presence? Is COM authority in effect in countries where the United States is engaging in hostilities? What is the COM's authority over the legislative branch?
Finally, specific concerns, possible options, and reform proposals for improving COM authority and effectiveness are explored. This report may be updated as events warrant.