Imperialism is found in the ancient histories of China, India, the Middle East, Egypt, Africa, and American Indian societies.
Imperialism is often linked with totalitarian enterprises, since the colonized rarely had much say in their governance.
Imperialism is the forceful extension of a nation's authority by territorial conquest or by establishing economic and political domination of other nations that are not its colonies.
The necessary expansion of capitalism beyond the boundaries of nation-states—a foundation of Leninism—was shared by Rosa Luxemburg (The Accumulation of Capital: A Contribution to an Economic Explanation of Imperialism) and liberal philosopher Hannah Arendt.
Claiming to be Leninist, the U.S.S.R. proclaimed itself foremost an enemy of imperialism, supporting armed, national independence movements in the Third World while simultaneously dominating Eastern Europe.
Imperialism not only describes colonial, territorial policies, but also describes economic dominance and influence.
Currently, "imperialism" applies to any instance of a greater power acting or being perceived to act at the expense of a lesser power.
The term "Imperialism" was coined in the sixteenth century, reflecting the imperial policies of Spain, Portugal, Britain, France, and the Netherlands into Africa and the Americas.
European intellectuals first developed formal theories of imperialism.
Currently, Marxists view globalization as imperialism's latest incarnation.
On the other hand, imperialism cannot be reduced to a Western phenomena copied by others.
Imperialism appears to have been universally practiced, even though some nations have never had empires.
Edward Said has explored how the imperial project resulted in a polarized view of the world in his Culture and Imperialism (1993) and other writings.
Marxist imperialism theory, and the related dependency theory, emphasize the economic relationships among countries (and within countries), rather than formal political and military relationships.
Harry Magdoff's Age of Imperialism (1954) discusses Marxism and imperialism.