Thai cuisine was not widely served outside of Thailand until the past few decades. A large number of foreign visitors were first exposed to Thai food in the 1960s, the beginning of the international tourism industry in Thailand. American servicemen experienced Thai food while in the country on R & R trips during the Vietnam War. Thai restaurants overseas began as sources of local food for Thai immigrants in London, Chicago, New York and Los Angeles; by the early 1990s there were over two hundred Thai restaurants in Los Angeles alone (Van Esterik 1992: 183). In the 1970s, there were only four Thai restaurants in London (Bhumichitr, Watcharin 1988) but now two to three hundred restaurants are serving Thai food in the city.