A Military Assistance Advisory Group (MAAG) is a designation for a group of military advisors from the United States sent to other countries to assist in the training of conventional armed forces and facilitate military aid. Although numerous MAAGs operated around the world throughout the 1940s–1970s, including in Yugoslavia after 1951, and to the Ethiopian Armed Forces, the most famous MAAGs were those active in South Vietnam, Cambodia, Laos, and Thailand, before and during the Vietnam War.

Records held by the National Archives and Records Administration detail the activities of numerous assistance advisory groups. In the NATO countries, MAAGs and similar bodies included JAMAG Europe; MAAG Belgium-Luxembourg; MAAG Denmark; MAAG France; MAAGs in Italy; the Netherlands; Norway; and Portugal, and the MAAG United Kingdom (1949-57); and military assistance units in Greece (from 1947); Turkey (from 1947); and Spain (from 1953). MAAGs and military assistance bodies beyond NATO were located in countries including Brazil; Cambodia; the Republic of China (see below); Ethiopia; Indonesia; Iran, until 1979; Japan; the U.S. Military Advisory Group to the Republic of Korea (KMAG); Laos (see below); Libya; the Joint U.S. Military Advisory Group to the Republic of the Philippines; the Joint U.S. Military Advisory Group, Thailand (see below); the U.S. Air Force Mission to Uruguay; and the American Military Assistance Staff, Yugoslavia.

Typically, the personnel of MAAGs were considered to be technical staff attached to, and enjoying the privileges of, the US diplomatic mission in a country. "The special status of personnel serving in Military Advisory Assistance Groups (MAAG) results from their position as an integral part of the Embassy of the United States where they perform duty." Although the term is not as widespread as it once was, the functions performed by MAAGs continue to be performed by successor organizations attached to embassies, often called United States Military Groups (USMILGP or MILGRP). The term MAAG may still occasionally be used for U.S. DOD organizations helping promote military partnerships with several Latin American countries such as Peru and the Dominican Republic.

Military assistance bodies in NATO countries In the NATO countries, MAAGs and similar bodies included JAMAG Europe; MAAG Belgium-Luxembourg; MAAG Denmark; MAAG France (at least 1949-54); MAAGs in Italy; the Netherlands; Norway; and Portugal, and the MAAG United Kingdom (1949-57); and military assistance units in Greece (from 1947); Turkey (from 1947); and Spain (from 1953).

MAAG, Greece In 1983, Joint MAAG in Greece US Navy Captain George Tsantes was killed by Revolutionary Organization 17 November.

Turkey

Spain MAAG Spain and the Joint U.S. Military Group (JUSMG) Spain were established by memorandum of Acting Secretary of Defense to Secretary of the Air Force, September 2, 1953, implementing two defense agreements and an economic agreement between United States and Spain, all concluded September 26, 1953. The establishment of MAAG Spain and JUSMG Spain, effective November 1, 1953, was confirmed by General Order 43, Department of the Air Force, November 6, 1953, with MAAG Spain responsible for administering mutual defense assistance program and JUSMG Spain responsible for constructing bases for U.S. use.

Military assistance bodies beyond NATO Beyond NATO military assistance groups were located in countries including Brazil (established June 1953); Cambodia; the Republic of China (see below); Ethiopia; Indonesia; Iran, until 1979; Japan; the U.S. Military Advisory Group to the Republic of Korea (KMAG); Laos (see below); Libya; Pakistan; the Joint U.S. Military Advisory Group to the Republic of the Philippines; the Joint U.S. Military Advisory Group, Thailand (see below); the U.S. Air Force Mission to Uruguay; and the American Military Assistance Staff, Yugoslavia.

Brazil U.S. military assistance to Brazil began during World War II.

Major General William A. Beiderlinden served in Brazil from 1952 to 1955, holding the positions of head of the Joint Brazil-United States Military Commission and Military Assistance Advisory Group Brazil. He was commended for his work to improve U.S-Brazil military relations, and his success was recognized when Brazil's military awarded him honorary graduate status of that country's Escola Superior de Guerra. He returned to the United States in April 1955 and retired in June.

MAAG Cambodia

MAAG Cambodia was established on June 4, 1955, pursuant to the United States-Royal Government of Cambodia agreement of May 16, 1955. This agreement included the introduction of high-ranking US military personnel to advise the Cambodian armed forces as non-combatants.Full text of the original 1955 treaty: http://untreaty.un.org/unts/1_60000/7/36/00013751.pdf The advisory group was staffed mainly by army personnel, with smaller contingents of navy and air force personnel.

As Cambodia's leadership took an official policy of neutrality in the Cold War, MAAG Cambodia's involvement in the country was terminated on November 20, 1963, by General Order 6, MAAG Cambodia, following the Cambodian government's cancellation of all U.S. aid.

Republic of China / Taiwan

At the end of World War II, a Col. Wise recruited for the Military Advisory Group to the Republic of China Air Force with headquarters located at Nanking and liaison teams at Hankou.

From 1951 until 1978, there was a Military Assistance Advisory Group to the Republic of China in Taiwan. From 1955, operational U.S. joint combat forces operating alongside the advisory group were directed by the United States Taiwan Defense Command.

The Military Assistance Advisory Group, Taiwan, commanded by Army Major General William C. Chase, was authorized 67 Army, 4 Navy and 63 Air Force personnel."Selected Aspects of U.S. Military Assistance," Historical Division, Joint Secretariat, Joint Chiefs of Staff, 13 December 1961 Classified Top Secret. Declassified 1993. Extracts reproduced via http://ustdc.blogspot.co.nz/2010/09/history-of-us-military-assistance-to.html . Under the group's joint headquarters were Army, Navy and Air Force sections. General Chase arrived at Taipei, Taiwan, on 1 May 1951 to begin carrying out his duties as the military member of a team, which was charged with insuring that all assistance granted the Chinese Nationalists was in furtherance of United States foreign policy.

After its arrival at Taiwan, the advisory group was reorganized and expanded. Initially there was no representation from the Marine Corps, until a U.S. Marine officer, Robert B. Carney Jr., was added to the team. Later on he was joined by a dozen other officers and enlisted men, bringing up the total to 13 Marine Corps personnel. The original three Service sections proved inadequate, so a joint technical service section was created as a counterpart to, and for advising, the Nationalist Army's Combined Service Force, which comprised the medical, signal, engineer, ordnance, transportation, chemical, and quartermaster services. A Headquarters Commandant, on the same level as the four section chiefs, was made responsible for the routine tasks necessary to support the group. Military Assistance Advisory Group officers assisted their counterparts within the Nationalist Ministry of National Defense and the general headquarters. Special teams were created as needed to provide aid at service schools and in tactical units.

On September 3, 1954, fourteen 120mm and 155mm Chinese Communist artillery in Xiamen (Amoy) and Dadeng (Tateng) fired six thousand rounds at the Kinmen (Quemoy) Islands in a five-hour period. Two Americans of the US Military Assistance Advisory Group, Lieutenant Colonel Alfred Medendorp and Lieutenant Colonel Frank Lynn, were killed in the shelling. Memorial cenotaphs were erected for the officers on Greater Kinmen by the ROC Army Kinmen Defense Command in 1992 and 2011 respectively. Lt. Col. Alfred Medendorp () was posthumously awarded the Order of the Cloud and Banner in November 1954.

General Chase retired in 1955 at which time he was succeeded by U.S. Brigadier General Lester Bork.Information furnished by BG Bork, USA Retired, to the Atlanta Taiwan Economic and Cultural Office (TECO) in November 2001. In 1967, Major General Richard Ciccolella commanded the MAAG.CINCPAC Command History 1967 , page 30/1026 By this time, the CINCPAC Command History for 1967 gives the title as "MAAG China".

American military advisors were tasked with providing arms and military advice, assisting with Taiwanese military training, implementation of the Sino-American Mutual Defense Treaty, maintaining military contacts, and monitoring Republic of China forces. In 1957 there were 10,000 Americans in Taiwan, the great majority being CIA and military personnel and their families.Operations Coordinating Board memo, "Report on Taiwan and the Government of the Republic of China (NSC 5723)," April 20, 1959, NatArch, Defense Dept. file 1959, box MNR2.

Since 1979, the site of MAAG headquarters in Taipei has been occupied by American Institute in Taiwan/Taipei Main Office, which moved to a new office complex in 2019. The American Club Taipei currently occupies the former site of the MAAG NCO Open Mess – Club 63.

MAAG Laos

MAAG Laos was preceded by the Programs Evaluation Office, established on 15 December 1955. Due to the limitations emplaced by international treaty, the PEO was set up with civilian personnel instead of a MAAG with military staff. When political changes superseded the treaty, MAAG Laos was established in 1961 to replace the Programs Evaluation Office in its support of the Royal Lao Army's fight against the communist Pathet Lao. On July 23, 1962, several interested countries agreed in Geneva to guarantee the neutrality and independence of Laos. As such, the US removed the MAAG, replacing it with a Requirements Office, which served as a convenient cover for the CIA activities.Conboy, Morrison, pp. 17–18.

One of MAAG Laos' commanders was Reuben Tucker.

Military Mission in Liberia Upon the request of the Liberian Government, President Harry S. Truman approved on October 19, 1950 a small US military training mission for Liberia. The mission (abbreviated LIBMISH) was to "undertake to reorganize and train the ..poorly organized and ill-equipped Liberian militia for internal security." In the event, the U.S. Army personnel of the mission remained, training the Armed Forces of Liberia, until the 1990s and the First Liberian Civil War.

MAAG Iran In 1943, a U.S. Army Mission (ARMISH) to the Imperial Iranian Armed Forces was established.

Major General Clarence S. Ridley, the first commander, "..found upon his arrival that the inflation had rendered officer salaries, and the budget generally, inadequate; that of serious equipment shortages, those in transport were drastic; that the organization and functioning of the supply and auxiliary departments were unsatisfactory; but that for all tasks likely to be imposed upon the Army during the war period, 1942 tactical methods and training were in general sufficient. In a report submitted in 1942, at the request of the Shah, to the Minister of War, Ridley specified four necessities as basic to Army reorganisation: limiting total strength to 88,000; retaining only the best officers; providing a reasonable scale of pay; and providing adequate motor transport."

In October 1946 the U.S. Ambassador wrote that the: "Iranians have formed great expectations of US Army mission under Grow and are already talking about request that it be doubled in size and giving it more responsibility."