This chapter introduces an analytical framework to explain the diversity of political regimes that emerged across 17 Asian countries and regions following decolonization in the 1940s–1950s. It challenges conventional explanations, such as colonial legacy or class structure, by emphasizing three domestic factors: the presence of self-rule institutions, the strength of monarchical authority, and the nature of the liberation movement (moderate vs. radical). These factors shaped which political actors (elected politicians, royal elites, moderate nationalists, or communists) led the decolonization process, and thus influenced whether post-independence regimes became democracies, monarchies, personalist dictatorships, oligarchies, or one-party systems. The chapter conceptualizes decolonization as a “critical juncture” with long-term consequences for institutional development. While the framework explains most regime outcomes, it also identifies outliers and sets the stage for specific analyses. Ultimately, the study highlights the importance of immediate pre-independence domestic politics over long-term structural or international factors in shaping Asia’s postwar political trajectories.