The oldest and largest of the military services, the Royal Thai Army traditionally served as the mainstay of the kingdom's defense system. The commander in chief and his large staff of military specialists, headquartered in Bangkok, directed the army in carrying out its mission. For tactical and administrative purposes, the army operated through four regional army commands. The First Army, headquartered in Bangkok, was responsible for the country's western and central provinces and the capital city (see fig. 17). The northeastern quadrant was the territorial home of the Second Army, and its regional headquarters were in Nakhon Ratchasima. The region of the Third Army, with headquarters in Phitsanulok, consisted of the northern and northwestern parts of the kingdom. The Fourth Army's region was southern Thailand its headquarters were in Nakhon Si Thammarat.

Tactically, the army was organized into seven infantry divisions (including five tank battalions), one armored division, one cavalry division (with an armor capability), eight independent infantry battalions, two special forces divisions trained and geared for small unit special and airborne operations, one field artillery division, and one air defense artillery division. Three airmobile companies provided the ground force units with battlefield support.

Although the army's primary mission was to defend the country against aggression by foreign ground forces, for many years invasion was considered an unlikely possibility by Thai civilian and military leaders, in part because of the defense umbrella provided by the United States. Moreover, many Thai leaders believed that such a threat probably could be circumvented politically without need for a military response. Furthermore, some assurance was derived from the fact that Cambodia and Laos, which were not regarded as serious potential threats, were between Thailand and Vietnam, the region's most belligerent power. Consequently, from the 1960s through the mid-1970s field action by army units concentrated mostly on dispelling insurgency. Devoting its training programs, equipment inventory, and operational capabilities to counterinsurgency, the army thus shelved its primary mission and for more than a decade concentrated on providing internal security.

Because there was such a melange of security forces combating the insurgency, the army's units were dispersed throughout the country--often in a manner that negated their value as frontline defenders in the event of invasion. For many years the single armored division was committed to counterinsurgency action in the North and operated as infantry most other tank battalions were on permanent duty in Bangkok, partly for internal political reasons. These scattered units could not have regrouped rapidly and effectively enough to support an infantry struggling to repel invaders. Similarly, artillery units were dispersed in small detachments designed to engage in limited action. The bulk of the infantry divisions were garrisoned in the interior at regional army command headquarters.

Con 12c0 ncentrating large numbers of troops in the interior rather than deploying them to border defense positions helped reduce financial costs because government regulations required that combat troops in field operations receive per diem payments of the equivalent of about US$1.00 in addition to regular salaries. (The police and civil servants also received this compensation when they were on government field operations or travel status.) The shortage of per diem money plagued defense and internal security operations, even during the years of United States military aid.

The army's top-heavy organizational structure and its role in political affairs also diluted its effectiveness as a conventional combat force. Because the country could not afford to maintain a large trained military, the army was organized to depend for the majority of its troops below the NCO ranks on conscripts serving their two-year service obligations. Most of these conscripts did not reenlist after their required commitments, and therefore a large percentage of their active service was spent in training. There were able officers at all levels of command, but the staffs at higher headquarters were inflated with high-ranking officers using their positions as opportunities for promotion and political advancement, particularly if they were assigned in Bangkok.

Key units of the First Army, stationed permanently in the capital, frequently provided the military backup for the coup d'etat attempts of senior army officers. At other times they were used by military leaders in power to forestall the coup aspirations of rival factions. The First Army also furnished detachments that served as the king's bodyguard and other units that took part in ceremonial activities in Bangkok.

Vietnam's invasion of Cambodia in December 1978 eliminated this complacent approach to national defense. Thailand scrambled to redeploy its combat forces and to provide its frontline units with the equipment and munitions needed to combat the Vietnamese threat along the Cambodian border. The Thai army's lack of readiness to provide border defense soon became apparent. Prime Minister Kriangsak flew to Washington in February 1979 to seek assistance in updating the army's military equipment inventory, which was ill-suited to modern defensive operations, particularly against the better equipped and more experienced Vietnamese. Despite the sympathetic response of the United States, the task of revamping the Royal Thai Army to meet potential threat was formidable, as the service's weapons inventory revealed.

To upgrade its state of combat readiness the army sought to increase its holdings of tanks and armored personnel carriers, improve its antitank capabilities, add heavier and longer range guns and howitzers to its artillery inventory, and enhance its ability to provide adequate battlefield defense against attacking enemy aircraft. These modernization efforts were hampered by economic retrenchment throughout the 1980s (see table 17, Appendix).

Other changes contemplated for the early 1990s included plans to upgrade the four infantry divisions stationed along the Cambodian border to mechanized or light infantry configurations. New training guidelines were designed to pare training time and establish a pool of trained reservists to draw upon as needed. General Chaovalit Yongchaiyut, in 1987 army commander in chief, called for reducing the number of "idle" generals by decreasing the number of general officers on active duty from more than 200 to about 80. Army troop strength was held at about 190,000 by lowering the conscription rate as the force moved toward becoming a totally volunteer army. Thai military planners proposed to upgrade the training and size of the army reserve force, studying systems used in Singapore and Israel.

Data as of September 1987