The Marine Security Guards’ (MSG) primary mission is to provide internal security services at designated U.S. Diplomatic and Consular facilities to prevent the compromise of classified information and equipment vital to the national security of the United States of America. The secondary mission of Marine Security Guards is to provide protection for U.S. citizens and U.S. Government property located within designated U.S. Diplomatic and Consular premises during exigent circumstances, which require immediate aid or action.
MSGs focus on the interior security of a diplomatic post’s buildings. In only the most extreme emergency situations are they authorized duties exterior to the buildings or to provide special protection to the senior diplomatic officer off of the diplomatic compound. MSGs carry a certain level of diplomatic immunity in the performance of their official duties.
The MSG Program in its current form has been in place since December 1948, but the Marine Corps has a long history of cooperation with the Department of State (DOS) going back to the early days of the Nation. From the raising of the United States flag at Derna, Tripoli and the secret mission of Archibald Gillespie in California, to the 55 days at Peking, Marines have served many times on special missions as couriers, guards for embassies and legations, and to protect American citizens in unsettled areas.
The origins of the modern MSG Program began with the Foreign Service Act of 1946, which stated that the Secretary of Navy is authorized, upon the request of the Secretary of State, to assign enlisted Marines to serve as custodians under the supervision of the senior diplomatic officer at an embassy, legation, or consulate. Using this Act, the DOS and Marine Corps entered into negotiations to establish the governing provisions for assigning MSGs overseas. These negotiations culminated in the first joint Memorandum of Agreement signed on 15 December 1948. Trained at the DOS’s Foreign Service Institute, the first MSGs departed for Tangier and Bangkok on 28 January 1949. Title 10, United States Code 5983, has since replaced the authority granted in the Foreign Service Act of 1946 and the most recent Memorandum of Agreement was signed on 9 Jan 2001. The Marine Corps assumed the primary training responsibility in November 1954.