How can we best explain the emergence and spread of nonviolent protest and violent conflict across the Middle East and North Africa region during the so-called 'Arab Spring'? What mechanisms facilitated the diffusion of democratic norms, ideas, and institutions across eastern Europe and the former Soviet states in the wake of the decline of communism? How, after being so deeply entrenched in western practice, can we account for the sudden and comprehensive abolition of the atlantic slave trade in the nineteenth century? This course explores a set of opportunities for and significant threats to international security. We will explore the mechanisms via which norms and political opportunities and ideas spread globally. We also examine the potential for various forms of violence and instability to spread across national borders. Our focus will be placed upon combining solid logical frameworks with cutting-edge empirical evidence to identify the channels and mechanisms via which diffusion and contagion occur. Students will be introduced to up-to-date analyses of process of contagion and diffusion with a view towards them being able to offer educated forecasts as to where instability is most likely to strike in the future.