Marine Security Guard Battalion

The Marine Security Guard Battalion (MSG BN), established in 1948, is a specialized unit of the United States Marine Corps tasked with providing security at U.S. embassies, consulates, and diplomatic missions worldwide. Its formation followed a series of security incidents at U.S. diplomatic posts, prompting the Department of State and the Marine Corps to formalize the assignment of Marines to protect American personnel and classified information abroad. Over the decades, MSGs have played critical roles in crisis situations, such as evacuations and attacks on embassies, including the 1979 Tehran embassy crisis. Today, the battalion remains a vital component of U.S. diplomatic security, with Marines serving at over 150 posts in more than 130 countries.