AbstractThe debate on the positive and negative dimensions of security tends to draw from securitization theory. Securitization theory has provided a service to this debate by exploring what happens when particular threats are labelled as a security issue by the securitizing actors. The positive/negative debate of securitization theory, especially in relation to migration, the environment and health, has been well established over the last decade. However, like other international relations (IR) theories, securitization theory is arguably 'western-centric' in outlook and scope, and the debate has not reflected the voices and experiences of other regional contexts. This thesis contributes to securitization debates by adding the perspective and experience of the Southeast Asia region. Southeast Asia provides a complex testing site for the securitization processes and debates in relation to a key public 'security' challenge, that of public health. The thesis empirically tests the consequences of .....