Due to its historical origins and existing challenges, the project of international administration has been described as an “arrangement of power rather than one of law”. This assertion is only partially founded. The deployment and design of such undertakings have been shaped by political and strategic considerations. However, these types of engagements are governed by legal rules and principles which regulate the exercise of public authority. This framework shall be examined in Part III. It addresses the foundations of territorial administration from two different perspectives: legality and legitimacy.

A closer analysis of these two issues shows that treatment of territorial administration has evolved over time. In the early era of the UN Charter, the legality of territorial administration was mainly viewed as a problem of statutory authority. States and legal scholars questioned the legal authority of the UN to exercise functions of public authority in the context of the proposed UN supervision of Trieste envisaged by the Peace Treaty with Italy. Today, the focus of the debate has shifted. The issue is not so much whether the UN may assume tasks of temporary governance in light of the UN Charter, but rather where the specific limits of the exercise of UN public authority lie and how the existing legal norms may be reconciled with the specific challenges of transitional administration.

Moreover, the very activity of international administration is increasingly perceived as a form of governance which requires further justification from the point of view of public legitimacy.