Imperialism is often associated with exerting control over people and territories. It is directly related to the use of force, be it military or not - maybe some sort of financial and cultural control.
We can see those characteristics in this excerpt. It is typical of imperialist minds and the propaganda they spread to claim that it is all done for a greater good. Even death. It is only another step on the way up. That can be clearly seen in the following sentences: "you can not destroy practises of barbarism, of slavery, superstition, which for centuries have desolated in the interior Africa, without the use of force" and " we may rest assured that for one life lost a hundred will be gained, and the cause of civilization and the prosperity of the people will in the long run be eminently advanced."
