A Marine Security Guard (MSG), also known as a Marine Embassy Guard, is a member of the Marine Corps Embassy Security Group (formerly Marine Security Guard Battalion),
a
brigade
A brigade is a major tactical military unit, military formation that typically comprises three to six battalions plus supporting elements. It is roughly equivalent to an enlarged or reinforced regiment. Two or more brigades may constitute ...
-sized organization of the
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the maritime land force service branch of the United States Department of Defense. It is responsible for conducting expeditionar ...
(USMC) whose detachments provide security at
American embassies,
consulates
A consulate is the office of a consul. A type of mission, it is usually subordinate to the state's main representation in the capital of that foreign country (host state), usually an embassy (or, only between two Commonwealth countries, a h ...
, and other official U.S. government offices, such as the United States Mission to
NATO
The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...
in
Brussels, Belgium
Brussels, officially the Brussels-Capital Region, (All text and all but one graphic show the English name as Brussels-Capital Region.) is a Communities, regions and language areas of Belgium#Regions, region of Belgium comprising #Municipalit ...
.
The USMC has a long history of cooperation with the
U.S. Department of State, which administers the nation's diplomatic posts; Marines have served on special missions as
courier
A courier is a person or organization that delivers a message, package or letter from one place or person to another place or person. Typically, a courier provides their courier service on a commercial contract basis; however, some couriers are ...
s, guards for embassies and delegations, and security for U.S. citizens in the
frontier
A frontier is a political and geographical term referring to areas near or beyond a boundary.
Australia
The term "frontier" was frequently used in colonial Australia in the meaning of country that borders the unknown or uncivilised, th ...
. Notable examples include
engagements at
Derna and
Tripoli, the secret mission of
Archibald H. Gillespie in the
Mexican-American War
Mexican Americans are Americans of full or partial Mexican descent. In 2022, Mexican Americans comprised 11.2% of the US population and 58.9% of all Hispanic and Latino Americans. In 2019, 71% of Mexican Americans were born in the United State ...
, and actions during the
Boxer Rebellion
The Boxer Rebellion, also known as the Boxer Uprising, was an anti-foreign, anti-imperialist, and anti-Christian uprising in North China between 1899 and 1901, towards the end of the Qing dynasty, by the Society of Righteous and Harmonious F ...
.
However, the formal and permanent use of Marines as security guards began with the
Foreign Service Act of 1946, which authorized the
Secretary of the Navy
The Secretary of the Navy (SECNAV) is a statutory officer () and the head (chief executive officer) of the Department of the Navy, a military department within the United States Department of Defense. On March 25, 2025, John Phelan was confirm ...
, upon the request of the
Secretary of State, to assign Marines to serve as custodians under the supervision of the senior diplomatic officer at a diplomatic post; pursuant to the act, the first joint
Memorandum of Agreement between the Department of the Navy and the Department of State was signed on 15 December 1948 regarding the provisions of assigning Marines overseas. Initially trained at the
Foreign Service Institute
The Foreign Service Institute (FSI) is the United States federal government's primary training institution for members of the U.S. foreign service community, preparing American diplomats as well as other professionals to advance U.S. foreign ...
, the first Marines arrived at
Tangier
Tangier ( ; , , ) is a city in northwestern Morocco, on the coasts of the Mediterranean Sea and the Atlantic Ocean. The city is the capital city, capital of the Tanger-Tetouan-Al Hoceima region, as well as the Tangier-Assilah Prefecture of Moroc ...
and
Bangkok
Bangkok, officially known in Thai language, Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies in the Chao Phraya River delta in central Thailand and has an estim ...
in early 1949; the Marine Corps has assumed primary training responsibility since November 1954.
The authority granted in the
Foreign Service Act of 1946 has since been replaced by and the most recent Memorandum of Agreement was signed in October 2020. The Corps is budgeted to train and maintain a limited cadre of guards to cover over 100 embassies worldwide. Embassy duty has been a crucial and longstanding aspect of the Marines’ mission. In response to the
2012 Benghazi attack, Congress ordered a near doubling of Marine Security Guards in the midst of a post-war drawdown in overall USMC numbers. The USMC has responded by redeploying one company from
1st Battalion 1st Marines while additional guards are trained.
Responsibilities

The primary mission of the MSG is to provide security, particularly the protection of
classified information
Classified information is confidential material that a government deems to be sensitive information which must be protected from unauthorized disclosure that requires special handling and dissemination controls. Access is restricted by law or ...
and equipment vital to the
national security of the United States at American diplomatic posts. This is accomplished under the guidance and operational control of a civilian federal agent of the
Diplomatic Security Service
The Diplomatic Security Service (DSS) is the principal Specialist law enforcement agency, law enforcement and security agency of the United States Department of State (DOS). Its primary mission is to protect diplomatic assets, personnel, and info ...
, known as the
Regional Security Officer (RSO) who is the senior U.S. law enforcement representative and security attaché at U.S. diplomatic posts around the world. In addition, MSGs provide security for visiting American dignitaries and frequently assist the RSO in supervising host country or locally employed security forces that provide additional security for the exterior of diplomatic missions. The MSGs fall under operational control of the RSO and are administratively controlled by the Marine Corps Embassy Security Group.
Marine Security Guards also provide protection for personnel and classified material located within designated diplomatic missions.
MSGs focus on the interior security of a diplomatic post's buildings. In only the most extreme emergency situations are they authorized to provide special protection to the senior diplomatic officer off the diplomatic compound. MSGs carry a certain level of
diplomatic immunity
Diplomatic immunity is a principle of international law by which certain foreign government officials are recognized as having legal immunity from the jurisdiction of another country. in the performance of their official duties.
Organization
The Marine Security Guards number approximately a thousand Marines at 174 posts (also known as "detachments"), organized into nine regional MSG commands and located in over 135 countries in 18
time zone
A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of ...
s, as well as its headquarters at
Marine Corps Base Quantico
Marine Corps Base Quantico (commonly abbreviated MCB Quantico) is a United States Marine Corps installation located near Triangle, Virginia, covering nearly of southern Prince William County, Virginia, northern Stafford County, and southe ...
.
Headquarters Company, along with MSG School, is composed of approximately 100 Marines providing administrative, logistical, legal, training and education support.
The remaining nine regions are commanded by a
lieutenant colonel, and typically entail a number of detachments in several countries. The companies are as follows:
Each Detachment is commanded by a
Staff Non-Commissioned Officer, being one of the few instances where an enlisted Marine may hold the title of "commander". Generally between the ranks of
Staff Sergeant
Staff sergeant is a Military rank, rank of non-commissioned officer used in the armed forces of many countries. It is also a police rank in some police services.
History of title
In origin, certain senior sergeants were assigned to administr ...
and
Master Gunnery Sergeant, Marine Detachment Commanders serve two tours, which generally last 18 months each. Unlike their subordinates, however, Detachment Commanders may be married. The minimum detachment size is seven MSGs (Marine Security Guards) and one detachment commander. This allows for posts to be manned at all times while allowing each of the Marines to conduct other routine training, internal management of the detachment and have some time off.
A Marine Security Guard usually serves three 12-month tours of duty. Marine Security Guard "watch standers" are enlisted Marines from the rank of
Private First Class to Staff Sergeant.
Duty
After every three years as a Marine Security Guard with the Marine Corps Embassy Security Group, any Marine is entitled to the
Marine Corps Security Guard Ribbon. According to the Marine Corps Uniform Regulations Order (Section 4-4a Line 24) Marine Security Guards are authorized to wear subsequent
service stars.
Marines of any
Military Occupational Specialty
A United States military occupation code, or a military occupational specialty code (MOS code), is a nine-character code used in the United States Army and United States Marine Corps to identify a specific job. In the United States Air Force, a sy ...
may volunteer for a three-year
tour of duty
For military personnel, a tour of duty is usually a period of time spent in combat or in a hostile environment. In an army, for instance, soldiers on active duty serve 24 hours a day, seven days a week for the length of their service commitment. ...
;
however, non-Staff NCOs with
dependents are not eligible, as well as Marines with potentially offensive
tattoo
A tattoo is a form of body modification made by inserting tattoo ink, dyes, or pigments, either indelible or temporary, into the dermis layer of the skin to form a design. Tattoo artists create these designs using several tattooing processes ...
s, legal or security restrictions, non–
United States citizenship,
dual citizenship
Multiple citizenship (or multiple nationality) is a person's legal status in which a person is at the same time recognized by more than one sovereign state, country under its nationality law, nationality and citizenship law as a national or cit ...
, significant financial indiscretions, and any other restriction that would prevent a
top secret
Classified information is confidential material that a government deems to be sensitive information which must be protected from unauthorized disclosure that requires special handling and dissemination controls. Access is restricted by law or ...
clearance.
Before being assigned to a Foreign Service post, a Marine accepted into the MSG program must successfully complete a training program located at the Marine Corps Embassy Security Group (MCESG), which is located at
Marine Corps Base Quantico
Marine Corps Base Quantico (commonly abbreviated MCB Quantico) is a United States Marine Corps installation located near Triangle, Virginia, covering nearly of southern Prince William County, Virginia, northern Stafford County, and southe ...
, Virginia. Marine Security Guard duty is one of a few special duty assignments available to qualified Marines. Marine Security Guard duty can be dangerous; there have been instances where Marines have been killed during this duty (most recently,
Cpl Steve Crowley in 1979,
Cpl Robert V. McMaugh in 1983,
Robert V. McMaugh
and Sgt Jesse Aliganga in 1998). Embassy duty is a crucial aspect of the Marine Corps' mission with a long tradition; the Corps is currently tasked to train and maintain a cadre of guards to cover 181 embassies and consulates worldwide with the ability to augment assigned forces as necessary.
See also
* Marine Corps Security Force Regiment
* White House sentries
* Embassy of the United States, Baghdad
Notes
References
Further reading
*
External links
Marine Corps Embassy Security Group
Official Website
on GlobalSecurity.org
on specialoperations.com
Marine Embassy Guard Association
*
{{US Marine Corps navbox
United States Department of State
Military units and formations of the United States Marine Corps
Military in Virginia
United States military presence in other countries