Taiwan is the big surprise for me. China makes sense, as there was a 20-year trade embargo and by the time it was over the Chinese tea industry had changed so radically that even if someone had been a regular tea-drinker in the 1940s it wouldn't have made much difference. Japan sort of makes sense, in that although there was never a formal embargo, a generation of Americans fell out-of-love with Japanese teas at a time when it had no other export markets and was in a chaotic postwar state. By the time that generation's children became interested in Japanese tea, twice-fired American-export sencha didn't exist anymore, so it wasn't a continuing of the old tradition but the start of a new one revolving around bancha and the Macrobiotics "Zen Diet", or later, around Japanese-style sencha newly available fresh through improvements in green tea packaging.
However, as far as I am aware, Taiwan and America never had any kind of conflict. The Taiwanese oolong industry was created in part to satisfy America's huge thirst for oolong tea, and then when the trade embargo with China started, it supplied the Lapsang Souchong, the Keemun, and the other popular Chinese teas in substitute form; some of them holding their own even today, like Taiwanese lapsang souchong. So I struggle to understand what happened here. Formosa oolong used to be so widespread that Lipton carried it alongside its Ceylon teas, and it is still offered (in a very stemmy form) today by many older tea vendors. But why so stemmy? And why is the general awareness of Formosa oolong so low when there was never any big event like the Chinese trade embargo or World War II to disrupt it?
That is on my tea-list of things I hope to discover one day.