How does imperialism affect our society?

Answer 1

Imperialism draws heavy criticism on the grounds that historically it has been frequently employed for economic exploitation in which the imperialist power makes use of other countries as sources of raw materials and cheap labor, shaping their economies to suit its own interests, and keeping their people in poverty.

Answer 2

To make it very short, the feeling of powerlessness among the vast majority and the tendency to leniently accept "fate",....
There are more and you can elaborate on it into thousands of pages but what I said here were the first things I immediately thought of.