Analysing the role in international law
International law is fluid, and “hard” sources of law like treaties can be shaped and even amended by the practice of nations. For example, the UN Charter contemplated that the United Nations itself would enforce Security Council authorizations to use force pursuant to military forces provided to it by member states. But these arrangements never materialized, and the relatively rare Security Council use-of-force authorizations are enforced by member states in an ad hoc fashion. Similarly, Article 51 of the Charter says: “Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security.” But through argumentation, interpretation and practice, this provision came to be seen as permitting self-defensive actions by states in (various modes of) anticipation of armed attacks. Follow-up “measures” by the Security Council have operated unevenly, at best.
These examples suggest that the text of the document is not always the last word on lawful uses of force under international law. It is also true that the prohibition on the use of force in Article 2(4) has been violated dozens, if not hundreds, of times since the UN Charter’s creation in 1945. Some people conclude from frequent violations of the UN Charter, and the absence of a reliable judicial or executive mechanism to enforce it, that the treaty’s prohibitions do little in influencing national behaviours. They certainly seem to do little if any work in cases like Ukraine, Crimea, Kosovo and Syria.
The fluidity and uncertainty about the UN Charter’s meaning presents an opportunity for those who want to argue that its meaning is changing to recognize a humanitarian intervention exception. The document’s text doesn’t support this conclusion. And the “responsibility to protect” doctrine that developed after the Kosovo invasion in 1999 is premised on compliance with the normal rules of the Charter.
Some people will point to the existence of a doctrine of developing humanitarian intervention – as suggested by the stance taken by the Great Britain, the United States and France that the strikes against Syria were “legitimate” – and scholarly support for humanitarian intervention, and so on.
These and related arguments are wholly inadequate, under any theory of international law, to overcome the document’s clear text. But still many people believe that practices and arguments like this can build up to change our understanding of international law, including the UN Charter.
Some people think the opposite. One argument against a humanitarian intervention exception is that once the non-intervention principles of the UN Charter are weakened by Western nations in the human rights context, non-Western nations would ignore those principles to serve their own interests. Consider Russian Foreign Minister Sergey Lavrov’s invocation of the 1999 Kosovo precedent to justify Russia’s 2014 intervention in Crimea. “If Kosovo is a special case then Crimea is a special case; it’s just equally special,” he said. But did Kosovo really impact Ukraine? Did the weakening of the non-intervention norm in Kosovo make it easier for Russia to grab Crimea? Perhaps, but this does not seem like a powerful explanation for what happened. A better explanation is that Russia invaded Crimea and the West acquiesced because Russia had local power and was more keenly interested in success, and the West was unwilling to push back because it was insufficiently motivated or organized to confront Russian aggression. International law did not stop the Crimea intervention.
The frequent violations of the UN Charter, their uncertain impacts on the practice of states, the ease with which humanitarian intervention exception arguments are made, and the lack of courts or an executive agency “above” the treaty to interpret and enforce it, lead many — especially outsiders to the debate — to wonder whether the document really functions as law. Such doubts are only enhanced by the frequent claim that some humanitarian interventions are “illegal but legitimate.”
In fact, international law is not all that different than the constitutional law of the United States.
Despite superficial appearances to the contrary, constitutional law, like international law, lacks a centralized legislature to specify and update legal norms, and although constitutional courts possess some ability to resolve the existence and meaning of constitutional norms, they are limited in special ways that prevent them from providing authoritative settlement. As a result, constitutional law suffers from the same kinds of foundational uncertainty and contestation over meanings that are viewed as characteristic of international law. Constitutional law also shares with international law the absence of an enforcement authority capable of coercing powerful political actors to comply with unpopular decisions. This lack of an enforcement authority raises doubts about legal compliance and, more generally, the ability of legal norms to constrain and not just reflect political interests. And, in much the same way as international law, constitutional law strains to legitimate the limits it purports to impose on popular self-government by invoking various forms (or fictions) of prior sovereign consent.
To state the obvious, the Charter of the United Nations is a multilateral convention to which all members of the Organization are parties. In other words, the Charter is a treaty. However, neither is all international law subject to the UN nor is the Charter the legal source of all international law. Much international law precedes the Charter and has been developed in parallel to it, including fundamental elements of international law such as the Genocide Convention which requires its signatories (and as jus cogens, all states) to prevent, stop and punish genocide seemingly irrespective of whether Genocide is an “essentially” domestic matter under Article 2(7) and whether the Security Council has authority to act in matters beyond “international peace and security.” The Charter does, however, have a degree of the third attribute of a constitution: supremacy. This supremacy covers not all international law (it is not pervasive or basic) but only the aspects of the Charter in which it imposes “obligations,” most particularly, peace and security.