Legal standards applicable to the fulfillment of the subsidiary responsibility
By its standards for good governance within states, public international law sets the framework also for the way in which the international community fulfills its subsidiary responsibility. These standards bind all subjects of this legal order, including the U.N., if they constitute customary international law. For governance standards arising out of human rights treaties, in particular those in connection with the fulfillment of social and economic rights, a binding effect on the U.N. is brought about by two legal considerations: First, human rights treaty obligations belong to the people living in a given territory, and stay there even in case of change of government or dismemberment of the state.35 Consequently, if governance functions are carried out not by the state but by the U.N., the latter are bound by the human rights treaties in force for that territory. This consequence has been suggested for insurgent movements (Tomuschat 2003b), but there is no reason not to extend the concept to any other actor, be it another state that is not a successor state, an international organization, or nonstate actor.
Second, this result is reached through the general principle of agency of necessity (negotiorum gestio), which applies when one actor (the “agent”) acts in the place of another (the “principal”) who is unable to take a required action. In this situation, the agent is under the duty to respect the obligations binding upon the principal (Buhring and Hufken 2008). This concept can be found in all legal systems of the world, and serves as a basis for a claim of the agent against the principal for reimbursement of his or her costs incurred in carrying out the action (Herdegen 1989, 313-16). Such a claim presupposes the agent’s respect for the principal’s interests when performing the action, because otherwise the agent would force an unwanted result upon the principal. From a normative perspective, the principal’s interests include observance of his or her legal obligations as these restrict the principal’s choice of actions were he or she to act. Logically, the concept of agency of necessity can be transposed to interstate relations and, consequently, it can be considered a general principle of law in the sense of article 38.i.c of the ICJ-Statute, which constitutes a source of international law. If negotiorumgestio thus is a rule of international law, it binds all subjects of that legal order, states and international organizations alike.
Public international law also regulates the actions of nonstate actors: if nonstate actors exercise governance functions in the absence of a functioning state, for example by ensuring physical security in a territory, by exercising adjudicative functions, or providing health services, they are bound by legal standards of governance.36 This result is not achieved by a direct applicability of human rights obligations to nonstate actors. Attempts to bind transnational corporations and other business enterprises directly to human rights have failed so far.37 Nevertheless, nonstate actors must be considered obliged by human rights under customary and treaty law if they exercise governance functions instead of the state. This result follows from the idea that human rights stay with the people on a given territory, and from the principle of agency of necessity (nejgotiorum gestio) as explained earlier. This conclusion is reinforced by article 9 of the ILC, Draft Articles on State Responsibility: under this rule, the conduct of a person is attributed to a state “if the person . . . is in fact exercising elements of the governmental authority in the absence or default of the official authorities and in circumstances such as to call for the exercise of those elements of authority" If, by law and irrespective of the state’s will, a private act is attributed to it, the state has a legal interest in that its international legal obligations are respected by the private actor.