The European powers had enough manpower between the World Wars to continue their hold on the colonies in Africa, the subcontinent and Southeast Asia. The European hold on Africa began to loosen in the 50s and 60s when “the winds of change” began to blow, and Africa exploded. There were a few peaceful transitions of power, and the occupying powers managed to leave their mark, culturally, on their former colonies.
well thats just it. all this emigration we see is a result of the prior colonial expansions and the wars in other continents.
the reason the UK is turning into Northwest Asia is because of Raj. the reason France is turning into Mahgreb North is because of 1800’s colonialism. The reason the US has pockets of Viets, Cambodians, Hmongs, and Somalis is because of our own little wars. These places lose their best minds to EU UK and US, and are left with second tier intellects to run their affairs with the usual predictable results.