This article is devoted to the conflict between the Republic of Armenia and the Republic of Azerbaijan on the ownership of the mountainous Karabakh zone. The confrontation between the two independent States is one of the complex conflicts that have both ethnic and political roots and are based on two basic principles, such as the right of the population to self-determination and state territorial integrity. The author considers the main causes of conflict in the work. The factors that influence the emergence and exacerbation of this conflict are also analyzed. Actions to resolve the conflict that occurred after active military actions were also studied. The article also describes the actions and interests of actors in international relations involved in the settlement of this conflict. The article also describes the diplomatic experience of Kazakhstan, and considers the policy of Kazakhstan to resolve the conflict in Nagorno-Karabakh.