imperial disease

noun3

1. •
   A disease that arises from colonial exploration and causes significant harm to an empire, especially the British Empire.
2. •
   A failing to which an empire is prone.

   • ...in July 1807 we may discern the growth of a singular British imperial disease: Russophobia. — 1991
3. •
   A communicable disease that is spread to indigenous people by conquering imperial forces.