At the time there was segregation around the world and they didn't want black people to play with white people because they thought they were inferior.
The allies wanted the axis powers military to demobilize and they would need to pay reparations for the war which was enforced at the Paris Peace conference.
Berlín conference of 1884 - 85 ( Congo Conference ) regulated European colonization for trade in Africa during the New Imperialism period
There was a war in 1928 or ask Google