Belgian rule in the Congo was based on the "colonial trinity" ("trinité coloniale") of state, missionary and private company interests. The privileging of Belgian commercial interests meant that large amounts of capital flowed into the Congo and that individual regions became specialised. On many occasions, the interests of the government and private enterprise became closely tied, and the state helped companies break strikes and remove other barriers raised by the indigenous population. The country was split into nesting, hierarchically organised administrative subdivisions, and run uniformly according to a set "native policy" ("politique indigène"). This was in contrast to the British and the French, who generally favoured the system of indirect rule whereby traditional leaders were retained in positions of authority under colonial oversight. During World War I, Congolese troops participated in offensives against German forces in the area of modern-day Rwanda and Burundi which were placed under Belgian occupation. The Congo had a high degree of racial segregation. The large numbers of white immigrants who moved to the Congo after the end of World War II came from across the social spectrum, but were always treated as superior to blacks.