Imperialism describes the domination of a one society or group over another, but this can happen in many different forms beyond colonial territory expansion. The key is that it involves the subjugation of an entire indigenous population. Some European intellectuals like Immanuel Kant and Denis Diderot critiqued imperialism for its cruelty to native populations. Philosophers as disparate as communist Karl Marx and utilitarian John Stuart Mill defended imperialism as an activity that would advance so-called "primitive" groups.

Cultural Imperialism

Cultural imperialism denotes how a dominant group's cultural practices come to dominate the cultural landscape of a subjugated population. In contemporary life, cultural imperialism can refer to the dominance of American or European popular culture in poor countries. One example is when American music dominates the charts in a developing society. When European art is idealized as fine art while African art is derided as "local craftsmanship," this suggests cultural imperialism. The term can also refer to the spread of Christianity from the colonial period until today.

Political Imperialism

The process through which a dominant country establishes political control -- called a sphere of influence -- over a poor country is political imperialism. Colonial expansion is one type, as is the establishment of puppet governments. Both the United States and Soviet Union used puppet governments during the Cold War. The intrastate wars that took place in Latin America during this period are now understood as proxy wars in which both countries tried to install sympathetic leadership via behind the scenes financial support and military training.

Economic Imperialism

Economic imperialism -- coined by political theorist Leonard Woolf -- refers to the way in which dominant powers establish economic power over developing countries. During colonial expansion, this meant exploiting forced labor and pillaging local resources to enrich the dominant countries. Left-leaning social scientists sometimes refer to the World Bank and International Monetary Fund as bodies that exert the West's economic domination over poor countries. They argue that this happens through structural adjustment programs that impose harsh austerity programs on sovereign states to force loan repayment.

When Types Overlap

Imperialism types can overlap with another and are often difficult to isolate. The George W. Bush Doctrine of preemptive warfare in Iraq -- with the goal of establishing a democracy there -- is sometimes viewed as political imperialism. But the drive for influence over the oil supply in the Middle East -- including preemptive war in Iraq -- can also be interpreted as economic imperialism. When American influences in music, television and film seep into native Iraqi culture, that's cultural imperialism.