When nuclear war seemed inevitable, and survival required the best and brightest, education and opportunity were vital. Those who were linked to the West, even colonies, had to be brought up to some standard. Their populations were needed.England distributed Klim, a milk powder, free, along with other nutrients to ensure that their colonists would be strong and capable of assisting.With man power down due to the losses in World War II, the best and brightest as well as those who were strong and capable were imported into the “mother country”.
Maybe they were imported to do menial labour, i.e. maids and nurse’s aides, construction workers and bus drivers. Maybe the Colonial Power needed to fill important roles; Doctors, Educators, so the process of skimming the top became standard.
Even today in 3rd World Countries the top scholars, professionals, etc. are virtually abducted by their previous colonial master.
In the Soviet Union, which also suffered a man shortage after World War II, women filled ‘male’ roles because they were needed.