The earthquake off the west coast of Sumatra on 26 December 2004 unleashed a tsunami in the Indian Ocean that affected more than a dozen countries throughout South and Southeast Asia and stretched as far as the northeastern coast of Africa. The two worst affected areas – North-East Sri Lanka and the Aceh region in Indonesia – have both been marked by protracted intra-state armed conflicts. In the immediate aftermath of the tsunami, international journalists and humanitarian actors argued that the disaster could actually constitute an opportunity for conflict resolution, as the scale and urgency of humanitarian needs should bring the protagonists together in joint efforts for relief, reconstruction and conflict resolution. In contrast, research on the impacts of natural disasters often concludes that disasters tend to deepen rather than resolve conflicts. Four years after the tsunami it can be observed that Aceh and North-East Sri Lanka have followed highly divergent trajectories. In Aceh, a Memorandum of Understanding between the Government of Indonesia and Gerakan Aceh Merdeka (GAM) was signed shortly after the tsunami and has been followed by peace and a process of political integration into Indonesian democracy. In Sri Lanka, the tsunami created a humanitarian pause from the gradual escalation of hostilities and an attempt to create a joint mechanism between the Government of Sri Lanka (GOSL) and the Liberation Tigers of Tamil Eelam (LTTE) for handling humanitarian aid, but Sri Lanka has since then returned to full-scale warfare between the GOSL and LTTE.