Following the establishment of the United Nations Charter (Charter) and its distinctive ban on the use of force in Article 2(4) of the Charter, there have been numerous attempts in State practice to splinter or modify its text. During the cold war, States frequently asserted that there were different exceptions to this rule, including those related to defending citizens abroad, humanitarian intervention, and various extended forms of self-defence, whether referred to as anticipatory or interceptive. The humanitarian intervention was increasingly activated during the post-cold war era. It has been argued that the Charter’s Article 2(4) was flawed from the very beginning and the Charter itself delivered several exceptions and uncertainties, which has left enough room for the article to be fatally undermined.1
While Article 2(4) of the United Nations Charter forbids the use of force under international law, Article 51 of the Charter allows for the use of force as a right of self-defence. It is generally contended that a State using force in self-defence against another State, has done this in conformity with the text of Article 51. States who support using of force under Article 51, also argue that the State being targeted by the non-State actor has the right of self-defence, if the State from which the non-State actor is acting is unwilling or unable to deal with the non-State actors. Few States have largely used this defence to support their use of force in the recent past, like the United States has for its military intervention in Afghanistan against the Taliban regime. Article 51 does not allow the States the right of self-defence in all instances but limits permission to member States in some stances. Furthermore, member States may also use force, if such use has been authorised by the United Nations Security Council under Article 42 of the United Nations Charter under collective action to restore peace and security.
Framework on the use of force
One of the aims of the Charter, as stated in the Preamble, was to protect future generations from the scourge of war and Article 2(4) of the United Nations Charter laid the foundation in implementing this objective. All member States under Article 2(4) of the Charter have to abstain 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”.2 Therefore, employing force to resolve a conflict with another State was not appropriate; instead, it is always advised that peaceful cohabitation be sought.
While Article 2(4) of the United Nations Charter prohibits the use of force by States, the Charter at the same time also, permits and regulates the use of force in certain circumstances, calling it as exceptions to the general prohibition. As a result, there are two exceptions to the general restriction. The first exception comes in the shape of Article 51 of the United Nations Charter, which permits the use of force in self-defence. The second one is the use of force that has been authorised by the United Nations Security Council, which is governed by Article 42 of the United Nations Charter. According to Article 51, self-defence primarily refers to the quick reaction of a victim State that has been the target of an armed attack. This immediate reaction could be either individual or group self-defence.
Framework on the right of self-defence
The idea of the defensive use of force is thought to have given rise to the right of self-defence. Self-defence has its roots in the defence of a State’s sovereignty since it was a State’s sovereign right to employ force defensively in order to protect itself.3 The Carolinecase4 is where self-defence was given a formal interpretation in the 19th century. Daniel Webster, the United States Secretary’s ideas laid the groundwork for the modern application of the right of self-defence under customary international law. The three key components of self-defence were introduced in his declaration, which are necessity, immediacy, and proportionality.5 Only after the Caroline dispute6, did jurisprudence regarding the use of self-defence as a form of self-preservation become established and even then, only under very specific conditions. Later, after the San Francisco Conference, States under Article 51 of the United Nations Charter were given the right to use self-defence against armed aggression. The International Court of Justice ruled unequivocally that both customary international law and the United Nations Charter recognise the right to self-defence as an inherent right.7
The United Nations Security Council under Chapter VII8 determines whether there is any aggression or threat to peace and if any, then identifies the source and recognises collective actions that will be taken to resolve such issues. However, the Security Council in procedural matters can take action with the consenting vote of nine members, along with the affirmative vote or abstention of each of the permanent five members. Potential conflicts among the Council members can also prevent a quick and efficient response to humanitarian crises, as happened in the case of Kosovo in 1999, where only Russia’s and China’s negative vote was sufficient to stop the Security Council from passing the approval of human intervention in the State.9
Self-defence against non-State actors
There has been a debate about the application of Article 51 of the United Nations Charter and whether the States can exercise their right of self-defence even when they are subjected to an armed attack by non-State actors. There was no question that an armed attack, for a very significant period of time, was meant as an attack between States only. It is very much understandable as Article 51’s scope in regard to Article 2(4) within the United Nations Charter in plain reading, is seen to be governing exclusively the inter-State use of force. However, there are arguments that the drafters of the two abovementioned clauses intentionally left a gap between them and despite the fact that Article 51 grants an exception to Article 2(4), it is of a different nature and includes non-State actors in its interpretation.10
The justification for using force in self-defence against non-State actors has been primarily justified in formalist legal assessments and not in policy or political considerations. The very first argument made in support of this explanation is based on how the existing law is being interpreted. The idea that an armed attack should only originate from States is not supported by the textual interpretation of Article 51 of the United Nations Charter. It emphasises that Article 51 only pertains to armed attacks and does not specifically mention attacks by the State. Without indicating that the armed attack must originate from a State, the language just says, “if an armed attack occurs”. Therefore, it is asserted that an armed attack can also be carried out by non-State actors and that the attack itself, rather than the attacker, is what matters.11 This opinion also connects to the resolutions the United Nations Security Council had passed following the September 11 attacks.12 Furthermore, a non-State actor’s actions may also be attributed to a State under international law if the two entities lie in close proximity to each other.13
Armed attack interpretation in Article 51
Webster in Caroline case14, has argued that anticipatory self-defence which is employing force to thwart an imminent danger of an armed attack is recognised by the customary concept of self-defence, although with conditions.15 However, the concept of self-defence as mentioned in Article 51 is “linguistically” believed to be more limited than the concept of the right of self-defence contended in customary law. This is so because Article 51 only authorises self-defence following an armed attack on the State. Article 51 states, “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.”16
On top of that, even some past instances, where the League Assembly outright criticised Japan’s claim of military action as self-defence against China in 1931 or where the States led by the United Kingdom rejected Germany’s attempt to use self-preservation as an excuse when it took control over Bolivia and Moravia in 193417, were in contrast to the United States argument18 and shows that a presence of an armed attack was implicitly a prerequisite to the lawful exercise of the right of self-defence. This has led to a discussion amongst scholars regarding the interpretation of Article 51, where one group gave a narrow interpretation of the text and restricted when force may be used, while the other group gave a broader interpretation of the article and considered anticipatory self-defence to be part of customary international law. A large number of States firmly support the United Nations Charter’s comparatively restrained approach to the use of force as self-defence, as the States believe, “if they will not, they will be the target of such uncontrolled force by the hegemonic States”.19
The Bush Doctrine on anticipatory or pre-emptive self-defence has raised many concerns in the recent past. As according to the said doctrine, if the United States believes that the other States are unable or unwilling to deal with the terrorist groups or non-actor groups in their jurisdiction, it has the right to take action instead.
Unilateral approach to the right of self-defence
The United States of America considers itself the primary supplier of global security and stability, so it affirms the right to take action even without receiving prior permission from the Security Council and acts unilaterally to assert armed intervention in other States. The North Atlantic Treaty Organisation (NATO) forces started an aerial bombing intervention against the Yugoslav military in Kosovo, following the ignored repeated warnings to Yugoslavia and the Yugoslav Government’s refusal to sign the United States’ Peace Agreement in 1999.20 This intervention is said to have violated Article 2(4) of the United Nations Charter and the sovereignty of Yugoslavia. Even the decision of the United States to dispatch soldiers to Lebanon was made unilaterally by the United States, based on the unilaterally decided facts, despite objections from international bodies.21 In the year 2020, the United States through an airstrike killed Qasem Soleimani in Iraq, who was the commander of Iran’s military operations, violating all forms of international humanitarian law and Article 2(4) of the United Nations Charter. The United States in its letter to the United Nations stated that the aforesaid action was exercised by it, so as to exercise its inherent right of self-defence. The United Nations in its report contradicted United States’ actions as not genuine and that there should be proper evidence and justification from the side of the States invoking Article 51 under the United Nations Charter.22 The United States in its letter had neither given proper reasoning and justification for its activities to be covered under self-defence, nor has it timely reported the attack. Yoram in his book has however argued that the text of Article 51 does not mention that the report provided by the acting party should contain clear evidence.23 Moreover, this view is supported by the drafting history of the United Nations Charter where a flexible article was adopted, rejecting the broader proposal to keep United Nations Security Council to be informed at all times.24
In view of the above discussion, there has always been recognition of the right of self-defence, whether under domestic or international legislation. However, one thing concerning the right of self-defence in international law that can be fairly concluded is that its specifics have rarely remained constant. The international law governing the right of self-defence is too vague and unclear to offer any specific instructions on whether using force is legal or not. The right of anticipatory self-defence was established in Caroline case25 but there is still debate on the applicability of this right under international law. Even after the introduction of Article 51 in the Charter of the United Nations, State practice does not imply the existence of a right that extends beyond what is expressly permitted.
It has been contended that wars inevitably occur, as they have since the beginning of time between parties, both of which are using force reportedly in “self-defence” and it is typically impossible for the international system to determine with certainty which State is the aggressor, and which is aggrieved.26 Even, collective actions controlled by the United Nations Security Council under Chapter VII of the United Nations Charter have left room for conflicts and misuse of power by the dominant States. Hegemonic countries like the United States of America take advantage of this ambiguousness to unilaterally enforce the use of force in other States, like in the case of killing Iraq’s general as the right of self-defence under Article 51 of the United Nations Charter, prohibiting Article 2(4) of the Charter. Therefore, it is imperative that the International Law Commission of the United Nations explicitly codify the exact rules governing the doctrine of self-defence in order to preserve and restore global peace, security, and inter-State cooperation.
† Pursuing LLM in Corporate and Financial Law and Policy, Jindal Global Law School (O.P. Jindal Global University). Author can be reached at firstname.lastname@example.org.
1. Thomas M. Franck, “Who Killed Article 2(4)? or: Changing Norms Governing the Use of Force by States”, (1970) 64 AJIL 809.
2. United Nations Charter, Art. 2(4).
3. Murray Colin Alder, The Inherent Right of Self-Defence in International Law (Springer, 19th Edn., 2013).
4. United States v. United Kingdom (1840) 29 BFSP 1137 (The Caroline Case).
5. Gillian D. Triggs, International Law: Contemporary Principles and Practices (LexisNexis Butterworths, 2nd Edn., 2011).
6. United States v. United Kingdom (1840) 29 BFSP 1137.
8. United Nations Charter, Art. 42.
9. Eyal Benvenisti, “The US and the Use of Force: Double-Edged Hegemony and the Management of Global Emergencies” (2004) 15 EJIL 677.
10. Sean D. Murphy, “Self-Defense and the Israeli Wall Advisory Opinion: An Ipse Dixit from the ICJ?” (2005) 99 AJIL 62.
11. Karin Oellers-Frahm, “Article 51 – What Matters is the Armed Attack, not the Attacker” (2017) 77 ZaöRV 49.
12. UN Resolution 1368 (12-9-2001); UN Resolution 1373 (28-9-2001).
13. International Law Commission, “Articles on Responsibility of States for Internationally Wrongful Acts” (53rd Session, 2001).
14. United States v. United Kingdom (1840) 29 BFSP 1137.
15. Gillian D. Triggs, International Law: Contemporary Principles and Practices (LexisNexis Butterworths, 2nd Edn., 2011).
16. United Nations Charter, Art. 51.
17. Subhas Chandra Khare, Use of Force under UN Charter (Metropolitan Book Company, 1985) p. 83.
18. Gillian D. Triggs, International Law: Contemporary Principles and Practices (LexisNexis Butterworths, 2nd Edn., 2011).
19. Christine D. Gray, International Law and the Use of Force (Oxford University Press, 4th Edn., 2018).
20. Eyal Benvenisti, “The US and the Use of Force: Double-Edged Hegemony and the Management of Global Emergencies” (2004) 15 EJIL 677.
21. Thomas M. Franck, “Who Killed Article 2(4)? or: Changing Norms Governing the Use of Force by States”, (1970) 64 AJIL 809.
22. United Nations, Human Rights Council, Report of the Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions (July 2020).
23. Durward Johnson, “The UN Soleimani Report and the US Article 51 Notification” (Lieber Institute West Point, 24-9-2020) <https://lieber.westpoint.edu/un-soleimani-report-u-s-article-51-notification/> (accessed on 9-10-2022).
24. Durward Johnson, “The UN Soleimani Report and the US Article 51 Notification” (Lieber Institute West Point, 24-9-2020) <https://lieber.westpoint.edu/un-soleimani-report-u-s-article-51-notification/> (accessed on 9-10-2022).
25. United States v. United Kingdom (1840) 29 BFSP 1137.
26. Thomas M. Franck, “Who Killed Article 2(4)? or: Changing Norms Governing the Use of Force by States” (1970) 64 AJIL 809.