Thailand in the late 1980s shared boundaries with Burma, Malaysia, Laos, and Cambodia. Although neither China nor Vietnam bordered Thailand, the territory of both countries came within 100 kilometers of Thai territory (see unavail.asp"> fig. 2). Many parts of Thailand’s boundaries followed natural features, such as the Mekong River. Most borders had been stabilized and demarcated in the late nineteenth and early twentieth centuries in accordance with treaties forced on Thailand and its neighbors by Britain and France. In some areas, however, exact boundaries, especially along Thailand’s eastern borders with Laos and Cambodia, were still in dispute in the late 1980s.
Disputes with Cambodia after 1950 arose in part from ill-defined boundaries; the most notable case was a dispute over the Preah Vihear Temple area submitted to the International Court of Justice, which ruled in favor of Cambodia in 1962. During the years that the Cambodian capital, Phnom Penh, was controlled by the Khmer Rouge regime of Pol Pot (1975-79), the border disputes continued. In the early 1980s, the People’s Republic of Kampuchea and its mentor, Vietnam, made an issue of boundaries in Prachin Buri Province in eastern Thailand. In contrast to these incidents, which attracted international attention, boundary disputes with Malaysia and Burma were usually handled more cooperatively. Continuing mineral exploration and fishing in the Gulf of Thailand, however, were sources of potential conflict with both neighbors. Adding to general border tensions were the activities of communist-led insurgents, whose operations had been of paramount concern to the Thai government and its security forces for several decades. The problem of communist insurgency was compounded by the activity of what the Thai government labeled "antistate elements." Often the real source of border problems was ordinary criminals or local merchants involved in illegal mining, logging, smuggling, and narcotics production and trade (see State of National Security , ch. 5).