If you want to know who controls the empire, look to the group that can play it both ways: nationalism and imperialism. All other groups must play only by the rules of imperialism.
In the British Empire, the Brits could be patriotic & nationalist(and guard British sovereignty) but also imperialist in transgressing against the national or tribal independence & sovereignty of other peoples. Since non-Brits couldn't insist on their own tribal or national independence/sovereignty, their only option was to submit to the imperialist agenda enforced by an external power.
So, even though there were many races and cultures in the British Empire, the Brits ruled whereas others were ruled. Brits guarded their power and independence in the empire whereas all other groups had to succumb to British power and obey.
And it was likewise in the Japanese Empire. Only the Japanese could be both nationalist and imperialist. Japanese territory, identity, and independence were inviolable.
In contrast, other Asian peoples within the empire had to play by rules of imperialism. They could not have national sovereignty or independence. So, Japan wasn't just part of the empire but its master. Empire was designed to glorify and increase Japanese pride and power at the expense of others who could only benefit as imperial subjects.
Read More: http://pithysayingsandmiscellany.blogspot.com/2017/07/rule-of-empire-only-master-race-is.html