I'm not so sure. If we are talking about the advantage in terms of the advantage in enhancing scientific knowledge, then certainly things have changed since WWII but pre-WWII, if my knowledge of history is correct, the majority of advances in theoretical science and mathematics happened in Europe. Even today a large number of scientists working in America are foreign-born. Now I don't know how much people trusted science and the scientific consensus in Europe vs America back then but I wouldn't be surprised if Europe was more progressive back then either.