This thesis analyzes two perspectives in the literature examining the development of social movements. The first perspective is based on the concept of political opportunity structure and emphasizes the influence of political structure and conditions on the development of social movements. The second perspective is based on new social movement theory and emphasizes the importance of collective identity, emotion, and culture on the development of social movements. Instead of emphasizing one factor over another, I argue that both collective identity and political structure/conditions have a significant impact on the development of social movements. I substantiate this argument through examining the development of the anti-base movement in Okinawa from the 1990s onward. The influence of both theoretical perspectives offers a cohesive explanation for the rise of the anti-base movement. First, I analyze each theoretical perspective separately in the context of the anti-base movement’s development then I present my own argument.