The conflict over Nagorno Karabakh stands out as the most intractable on the territory of the South Caucasus as it represents a combination of separatism and irredentism and has exacerbated the relations between two neighbouring countries - Armenia and Ajerbaijan - whose geo-political orientation, subject to cross-cutting regional and external interests and influences, is still in the balance. Nagorno Karabakh is the first full-blown conflict where the Organization for Security and Cooperation in Europe (OSCE) has been primarily involved as a mediator and the first conflict related to the OSCE's concrete talks to operationalize its concept of peacekeeping. This article argues that the OSCE normative context is one of the factors that has made the conflict resolution a daunting task. Focus is placed on the effect international norms and principles have on the conflict dynamics and on conflict resolution efforts in general. The article further examines the main constraints on reconciling the adversarial ositions of the conflicting parties and concludes that there is a need for creating a framework to search for cooperative solutions based on common needs and interests.