Professor Adil Haque’s excellent recent two-part series at Just Security illuminated the original meaning of Articles 2(4) and 51 of the U.N. Charter. Through careful attention to the Charter’s negotiating history, he clarified two issues. First, an “armed attack” that triggers the inherent right of self-defense preserved in Article 51 refers to a significant or grave use of force—an “act of aggression”—by one State against another, not to minor (but still prohibited) threats or uses of force, or to attacks by non-State actors located within the territory of another State. Second, the inherent right of self-defense preserved in Article 51 is not merely an exception to the Article 2(4) prohibition on the threat or use of force. It is more completely understood as a limited exception to the Security Council’s powers to maintain international peace and security enumerated in Chapter VII of the Charter, where Article 51 is situated.
Haque certainly provided a more complete original picture, but it is still rather incomplete. To understand the original effect of the Charter on the status of States and other entities and their rights of self-defense, we must consider more of the legal and geopolitical context surrounding its adoption. The Charter’s adoption originally resulted in differing sovereign status, rights and obligations as well as varied rights of self-defense. This diversity of rights and obligations arose from the fact that not all states were originally U.N. members and not all territories were yet States. As a textual matter, States had leeway to use defensive, perhaps even punitive force against non-State actors, or within the territory of non-State entities. Such defensive rights predated the Charter and appear to influence the practice of powerful States toward weakly-governed States and non-State entities to this day. (A caveat: this analysis is descriptive only. It is does not argue in favor of past or current state practice, or of the trust system created by the Charter.)
Limited Original U.N. Membership and Evolving State Status
At its inception, the United Nations had limited membership. In 1945, only 51 States were members of the United Nations. Afghanistan and Pakistan became members in 1946. Some former Axis Powers and African colonies did not become members until the 1950s and 1960s. Vietnam become a member in 1977 (Cambodia and Laos were admitted in 1955). North and South Korea were not admitted until 1991, although both had become states in 1948. Due to concerns about its neutrality, Switzerland did not join the U.N. until 2002. And although Sudan originally became a member in 1956, South Sudan is the most recent U.N. member, admitted in 2011 after seceding from Sudan to become its own sovereign state.
Put simply, in 1945, not all States were U.N. member States, and even more importantly, not all territories were States. Chapters XI through XIII of the Charter addressed “non-self-governing territories,” some of which would become “trust territories” under the Charter. They included territories displaced by the Second World War—such as the Korean peninsula and what was known as French Indochina until 1950, both of which had fallen under Japanese control—and also territories formerly under mandate (Article 77). Trustee States were to manage trust territories for the benefit of their inhabitants and in a way that maintained international peace and security, among other things (Articles 75-85). Such territories did not possess formal sovereign equality until admitted as U.N. members (Article 78). Some, however, achieved state status to varying degrees, which sometimes shifted with the geopolitical winds, such as occurred with Vietnam.
Diverse Sovereign Status, Obligations and Defensive Rights
Having the status of a territory, non-member State, or member State was consequential under the Charter’s text. The purposes of the Charter listed in Article 1 are primarily to maintain international peace and security and to use collective measures toward that end. Only member States enjoy formal sovereign equality under the Charter, however, and only member States agree to resolve their disputes peacefully (Articles 2(1) & 2(3)). (There were, of course, preexisting international obligations for some non-member States to settle disputes peacefully, such as those arising from the Hague Conventions of 1899 and 1907 and the Kellogg-Briand Pact.)
Important for the sake of this discussion, only member States are addressed by Articles 2(4) and 51. Article 2(4) provides “[a]ll Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the purposes of the United Nations” (emphasis added). Article 51 preserves the inherent right of self-defense when “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” (emphasis added). Non-member States and territories were not required to participate in or support the Charter’s collective security system (for example, Art. 2(5) and Article 25, which requires only the “Members of the United Nations” to “carry out the decisions of the Security Council”). They also retained their inherent right of self-defense under customary international law.
That Articles 2(4) and 51 address U.N. member States in these ways strengthens the conclusion that Article 51 self-defense is an exception to collective security measures under Chapter VII. Article 2 requires member States to respect the sovereignty of other members and to resolve disputes peacefully using the mechanisms contemplated by the Charter rather than the threat or use of force against any State (member or non-member). Article 51 allows member States a limited right to use force in self-defense when an armed attack actually occurs, but only until the Security Council takes effective collective action to restore international peace and security, should that be necessary.
The Charter nowhere explicitly addresses the use of force by or against non-State actors, or the self-defense rights of non-member States or non-State territories. Article 2(6) provided only that the U.N. was to “ensure that states which are not Members of the United Nations act in accordance with these Principles so far as may be necessary for the maintenance of international peace and security.” Clearly, the maintenance of international peace and security—not strict regulation of the use of force against non-State actors or other entities—is the overarching object and purpose of the Charter.
These differing rights and obligations of member States, non-member States and non-state entities provide an important supplement to Haque’s analysis of Articles 2(4) and 51. Article 2(4) explicitly protects the territorial integrity and political independence of “any state,” not just member States. Thus, prior to becoming UN members, Switzerland and other established, internationally recognized States were protected by Article 2(4)’s prohibition on the threat or use of force. Article 2(4) does not explicitly mention non-State “territories” or non-State actors. While a use of force within or against a non-State entity might fall within the prohibition of uses of force that are “in any other manner inconsistent with the purposes of the United Nations,” as a textual matter, member States originally had at least some latitude to claim that discrete, defensive uses of force against non-State actors not located within the territory of a State—such as pirates at sea or violent dissidents within a non-State territory—were consistent with Article 2(4). Properly limited, they might also argue that such uses of force were also in accord with the object and purposes of the Charter. In other words, at least some discrete uses of defensive force against or within non-State entities were permitted by the Charter. They were arguably consistent with Articles 2(4) and 51 because they were: (a) not a violation of the text of Article 2(4); (b) within a State’s customary international law right to defend or protect its territory, population, instrumentalities or nationals; (c) unlikely to implicate international peace and security (as understood then); and (d) for all of these reasons, beyond the Security Council’s Chapter VII collective security authority.
Haque’s analysis clarifies that States negotiating the Charter were primarily concerned about significant attacks by States that would implicate international peace and security. That does not mean, however, that they intended to yield their inherent right of self-defense in all other circumstances. Recognizing that Article 51 is part of the Chapter VII collective security system logically implies that States might still exercise their inherent right of self-defense when international peace and security would not be implicated, particularly against non-State actors.
A Continuation of the Pre-Charter System?
This diversity of sovereign status, sovereign obligations and self-defense rights may have been intentional even if implicit. Ian Brownlie and others have noted that prior to the Charter’s adoption, there was fairly well-established practice of powerful States protecting and defending instrumentalities, nationals, and other interests abroad from local and immediate threats by non-State actors. An introduction of military forces to accomplish this typically occurred in response to armed violence within what were then considered non-state territories or “weakly governed” states. States had also regularly engaged in defensive or punitive actions or expeditions against pirates, bandits, and others in weakly-governed territories and sometimes also in response to alleged depredations by indigenous peoples. (By way of example, an incomplete list of pre- and post-Charter U.S. practice that encompasses this practice is available here.)
Prior to the Charter’s adoption, such measures were arguably not declarations or acts of “public war” because they did not involve the use of force between or against established, recognized states, sometimes called “civilized” nations in the Western parlance of the pre-Charter era. While the Charter’s principal aim was to prevent conflict between states, it arguably left room for states to defend their nationals and instrumentalities in other circumstances.
The broad purposes and text of the Charter certainly limit such defensive or protective measures but, taken as a whole, do not expressly or entirely prohibit them. To give a simple example, the Charter does not prohibit a State from defending a vessel on the high seas from an attack by pirates. For that matter, States probably would not understand it to prohibit resort to proportionate self-defense in response to a brief, minor border incursion by another State’s armed forces (such as occurred in the infamous Caroline incident), or to hostile confrontations between public armed vessels at sea. Is this because such incidents are within a longstanding customary right of self-defense and de minimus under the Charter because they do not implicate Chapter VII collective security powers? Or, is it because they are within the inherent right of self-defense preserved by Article 51 of the Charter? Haque’s analysis suggests that the original understanding of the Charter may have dictated the former view. Unsurprisingly, States now choose to base their actions in the Charter’s text and consistently argue that most or all defensive actions fall within the scope of Article 51.
Contemporary State Practice and Conclusion
Even though almost all terra firma is now within the borders of U.N. member States, a flexible view of sovereignty and defensive force continues to influence some State practice toward non-State entities and weakly governed states. Although contemporary transnational, lethal threats posed by non-State actors would seem to fall within the Security Council’s Chapter VII authority, the Council has never fully or consistently addressed them. Therefore, when powerful States conclude that another U.N. member State is a “failed state” or is “unwilling or unable” to address a perceived threat situated within its borders, they have used increasingly novel legal arguments—which now include a theory of preemptive self-defense that often might be more accurately equated with a punitive armed reprisal—to use force within that State and sometimes even against it. The upshot is that the territorial integrity and political independence of some States is not yet equally respected in practice, just as was the case prior to relatively universal State status and Charter membership.
Old habits appear to die hard in international relations. Perhaps this effective reversion to pre- and early-Charter practice is the inevitable, realpolitik consequence of a dysfunctional Security Council that has been unable to consistently fulfill its obligation to cooperatively address and collectively resolve threats to international peace and security. Perhaps it is also traceable to earlier, often racist, notions of “civilized” and “uncivilized” nations or peoples and more liberal rules allowing the use of armed force against those deemed to be in the latter category. Indeed, some U.S. Executive Branch lawyers cite pre-Charter practice as evidence of the president’s constitutional authority to use armed force without congressional authorization and in clear violation of the Charter. While the causes are surely varied, the result is an international system wherein de jure sovereign equality is now universal but does not exist in practice. Haque’s analyses therefore provide important insights, but they must be placed in their broader international legal and geopolitical context to more fully understand how the Charter originally affected State sovereignty and the use of force, and to better appreciate what has happened since its adoption.