The Second World War led to the last great wave of European emigration to the New World, taking away even more of the best and brightest who had the initiative to start all over in foreign lands.
The Netherlands is an excellent case in point. Thousands of Dutch--among them the most moral and upright Christian people you'd ever meet, Catholic or Calvinist--emigrated to Canada, Australia and the USA after World War II, while the enervated, effete, elderly and collaborators stayed behind.