A policy of extending a country's power and influence through diplomacy or military force.
Imperialism in an unequal human and territorial relationship. Its mostly involving the extension of authority and control of one state or people over another. An example being The cosmopolitan Roman Empire. The term as such primarily has been applied to western political and economic dominance in the 19th and 20th centuries. it is mostly accepted in modern-day that colonialism is an expression of Imperialism and cannot exist without the latter. The word Imperialism became common the united kingdom in the 1870's and was used with a negative connotation. Today, Imperialism isn't such a big deal but it can still come around.