World War I. However, the Ikhwan committed many excesses and atrocities not just on The Hejazi army but on other Arabs as well. The various tribal groups of the Ikhwan also had a tendency to go off and do their own things and thus needed to be brought under a more centralised control. The SANG acquired its moniker of the "White Army" during this period due to its wearing of traditional Arab dress instead of Western-style military uniforms. In 1954, the office of Jihad and Mujahidin was transformed into the modern National Guard. It was called White Army until 1963 when a British military mission reorganized it. Training of the National Guard became the responsibility of the US Vinnell corporation in 1975. About 1,000 United States Vietnam veterans were initially recruited to serve in the long-term training program designed to convert the guard into a mobile and hard-hitting counterinsurgency force that could also reinforce the regular army if necessary. These contractors were supervised by a United States military group with the designation Office of the Program Manager—Saudi Arabian National Guard (OPM-SANG). Extensive military infrastructure facilities have been built to ensure the comfort and well-being of national guard units. Their major cantonments were in Al-Ahsa Oasis near Al-Hufuf and the major oil installations of the Eastern Province and at Al-Qasim in the Nejd, in an area where many of the tribal elements were recruited and most training was conducted. A large new housing project for guard personnel, with associated schools, shops, and mosques, has been constructed near Riyadh, also the site of the guard's military academy, the King Khalid Military College. Other National Guard military cities were located at At-Ta'if, Dammam, and Jeddah, while a new headquarters complex was built in Riyadh in the early 1980s. During the 1950s and early 1960s, the regular army and the national guard were both small and of roughly equal strength. The guard suffered when the army's expansion was given priority, but in the 1970s the decline was reversed when the guard was converted to a light mechanized force with the help of United States advisers. Initially consisting of four combined arms battalions, the active-duty component had by 1992 been enlarged to two mechanized brigades, each with four infantry battalions, an artillery battalion, and engineering and signals companies. The guard's mobility over desert terrain was assured by 1,100 Commando V-150 armoured cars. Firepower came from