Dependency theory is a perspective in comparative politics and international relations that emerged in the mid-20th century as a critique of modernisation theory, particularly in the context of the development of Third World countries. It primarily focuses on the ways in which economic and political relationships between developed (core) and underdeveloped (periphery) nations maintain or exacerbate inequality. The theory highlights the structural forces that constrain the development of peripheral nations, pointing to a system of dependency where underdeveloped countries are reliant on the economic decisions, policies, and structures of richer nations, leading to a cycle of inequality and exploitation.

At the heart of dependency theory is the argument that the underdevelopment of poorer nations is not the result of internal inefficiencies or cultural factors, as suggested by modernisation theorists, but is instead the consequence of their integration into the global capitalist system. This system, as it operates today, ensures that the economic structures of developing countries are shaped by the needs and demands of wealthier nations, rather than by the internal needs of the developing countries themselves. As a result, these nations become dependent on foreign capital, technology, and markets, which in turn inhibits their ability to develop independently.

Dependency theorists, such as Raúl Prebisch,