The Chinese Road (or The Chinese Roads) were a series of highways built as a foreign aid project by the People's Republic of China (PRC) in northern Laos, beginning in 1962. The first new road was built from Mengla, Yunnan Province, PRC to Phongsali, Laos; it was completed on 25 May 1963. The next major road built was Route 46, begun in the 1966 dry season and stretching from the southern tip of Yunnan Province southward toward the border of the Kingdom of Thailand. As 25,000 Chinese troops and 400 antiaircraft guns came to be posted to defend Route 46, and Thai support of American war efforts in both the Laotian Civil War and the Vietnam War became widely known, there was uneasiness among both Thai and American intelligence communities concerning Communist China's intents in constructing the all-weather highway. American interest in the new road extended up to the White House.
Central Intelligence Agency (CIA) trained guerrillas spied on Route 46, and there was an attempt to block it with the abortive Operation Snake Eyes. However, Chinese antiaircraft fire upon overflying aircraft and steady increases in Chinese troops guaranteed its security from attack. In turn, while there were some preemptive joint military operations during 1972 by troops of both the Royal Lao Army and the Royal Thai Army along the Lao/Thai border just south of Route 46, the road was not used to invade Thailand. The Chinese did chase the local Lao population from the Pak Beng Valley verging on the road to expedite Chinese occupation, but stopped the road at the Mekong River short of the Lao/Thai border. While there were several theories about China's intent in building Route 46, the only firm conclusion was one by an anonymous American military intelligence analyst: "Northern Laos has a new border."