The study of national security is a sub-discipline of the wider subjects usually still referred to as International Politics. This study is based on a single case study method. Case study is preferred when the research is supposed to be done to enquire on a specific aspect. For this research, a process of tracing approach rather than conducting a comparative study with other small states has been adopted. It may be added that the Sri Lankan long-standing ethnic conflict with all its characteristics constitute an ideal case for the analyses of relationship between the ethnic conflict and national security dilemmas of small states. It is clear that the Tamil separatist struggle on an ethno-regional basis in Sri Lanka in its violent and protracted nature has been vital to the security and stability of the state. The ethnic conflict has grown to be a serious threat to the internal and external security as well as policy capacity of the state. However, since the independence of Sri Lanka in 1948, political rivalry between the political parties has long hindered peace efforts in the country.