Theories of development and underdevelopment offer competing explanations for the vast economic disparities between nations. Modernization theory, prominent in the mid-20th century, posited a linear path to development for all societies. It argued that traditional societies could develop into modern ones by adopting Western values, technologies, and political institutions, suggesting that internal factors such as culture and lack of capital were the primary barriers to growth. In stark opposition, Dependency theory emerged, primarily from Latin American scholars, contending that underdevelopment was not an original state but a condition actively created by the global capitalist system. This perspective argues that resources flow from a periphery of poor and underdeveloped states to a core of wealthy states, enriching the latter at the expense of the former. Underdevelopment is thus the flip side of development. Building upon and expanding this core-periphery model, World Systems Theory conceptualizes the global economy as a single, interconnected system. It introduces a third category, the semi-periphery, which consists of states that are exploited by the core but simultaneously exploit the periphery. This three-tiered structure of core, semi-periphery, and periphery creates a more complex and dynamic model of the world capitalist economy, where states can potentially move between categories, though the overall structure of inequality remains stable.