Cannabis use in Thailand is widespread and usually tolerated in a social setting. Prior to the beginning of U.S.-led clampdowns, cannabis was a standard item on the shelves of many Thai kitchens, and was widely available from local markets. Although cannabis has been specifically outlawed since 1937 (the Marijuana Act B.E. 2477), penalties were comparatively light and poorly-enforced.
During the Vietnam War (1955-1975), American troops stationed in Thailand were responsible for the introduction of Thai cannabis to the USA, where it is believed to have been an instrumental factor in the “hippie” counter-culture movement which began in the mid-1960s (which in turn led to the global clampdown on cannabis that only now appears to be relaxing its grip). A rough equivalent, the pleng phua Cheewit (“songs for life”) movement, sprang up in Thailand in the 1970s, in response to the increasingly repressive government policies of the time.