Cowen explains why certain countries’ cuisines have spread worldwide while others haven’t:
Consider how cooking evolves: It starts in the home and then eventually spreads to restaurants and on to cookbooks, along the way transforming a recipe from oral tradition to commercialized product. In the home, recipes are often transmitted from grandmother to mother, or from father to son, or simply by watching and participating. I’ve seen this in rural Mexico, for instance, when an older daughter teaches her younger sister how to pat tortillas the right way. When societies get richer, you start to see restaurants, a form of specialization like auto mechanics or tailors (see: Adam Smith on the division of labor). Restaurants require that strangers — other cooks — be taught the process. That means simplifying or standardizing ingredients so they’re easier to work with and, in many cases, available year-round. This, of course, means writing down the recipe. Once a dish reaches these commercial milestones, cookbooks will follow.
Thai cuisine hit U.S. shores in the late 1960s, thanks to American troops on R&R in Bangkok during the Vietnam War who brought the taste home, and it wasn’t long before restaurants followed. Soon, a booming economy and international trade made it a whole lot easier to find galangal and lemongrass, which allowed Thai restaurants to thrive. Today, any major U.S. city has at least a half-dozen places where you can find a decent green chicken curry. And once a cuisine proliferates, people want to be able to cook it at home.