Superficial information of the civil wars in Aceh, Indonesia and Sri Lanka creates the idea that both conflicts were in similar situations when they were hit by the Indian Ocean tsunami in 2004. It thus seems surprising that in the wake of the tsunami, the Free Aceh Movement and the Government of Indonesia signed a peace agreement, while the Liberation Tigers of Tamil Eelam and the Government of Sri Lanka returned to war. This thesis aims to explore what factors related to the tsunami contributed to this difference and whether rational choice theory can serve as an explanation for this difference. In order to find out, I conducted a qualitative comparative case study though the analysis of secondary documents. The results suggest that the f...