What international theory attributes security competition and interstate conflict to the lack of an overarching authority in the international arena?

Structural Realism

Explanation:

International politics is basically a struggle for power, but they don't always endorse the conventional logical view that this is a human psychology outcome. The lack of an overall authority over countries and relative power sharing in the international system refer defense rivalry and intergovernmental disputes to them.

Structural realism maintains that its theory of chaos and capability allocation (measured for the number of large competences within the international system) determine the essence of the international framework. The international system has a dynamic anarchically organising theory, which ensures that there is no hierarchical central authority.