Sample Undergraduate 1st International Law Essay

Investigation into the Debate over the Legality of the Use of Force in International Law

Introduction

This is an investigation into the continued debate over the legality of the use of force in international law.  In what is termed the post “UN Charter” period, there is argued to be a clear prohibition on the threat or use of force against the territorial integrity or political independence of any other state as is set down in Article 2(4) of the UN Charter itself.[1]  However, despite this seemingly clear prohibition, the use of force is clearly still prevalent in the world at large.  In addition, the United States and North Korea exchanged threats during the nuclear crisis of 2017.[2]  This essay will assess the limits of the prohibition on the use of force in modern international law, and in the light of these events, will assess whether or not it can be said that the prohibition on the use of force is still effective.

The General Prohibition on the Use of Force

The United Nations (UN) was established in 1945 in the wake of the Second World War in order primarily to ensure that war between States could not again wreak the terrible destruction that had been seen in the first half of the twentieth century.[3]  The general prohibition on the threat or use of force contained in Article 2(4) of the UN Charter is therefore seen as central to the entire mission of the UN, with the principle of prohibiting the unilateral use of force itself being regarded as being the very “raison d’etre” of the UN.[4]  The prohibition appears at first glance to be relatively clear in its scope, as it prohibits the use, or threat of the use of force, against the territorial integrity or political independence of any State, or in any other manner inconsistent with the purposes of the UN.  This is however subject to certain exceptions, such as the United Nations’ ability to take collective security measures, including the use of force, if sanctioned by the Security Council under Article 42 UN Charter.[5]  Similarly, Article 51 preserves the inherent right of individual or collective self-defence if an armed attack occurs, until the Security Council has taken the measures necessary to maintain international peace and security. States must immediately report measures taken in self-defence to the Council.[6]

It is possible however that these exceptions can be regarded as giving some scope to States to seek to evade the general prohibition on force.  As can be seen by the state of current events in the world today, the use of force, and the threat of the use of force remains prevalent.  Many of the current conflicts in the world can be seen as being initiated primarily for the purposes of altering the political status, independence, or territorial integrity of the States in question and thus these conflicts would appear at first glance to be caught by the reach of Article 2(4) UN Charter and the parallel customary prohibition recognised by the International Court of Justice (ICJ) in its landmark judgment in Nicaragua v United States.[7]  For example, Russia’s attempted annexation of Crimea in 2014 and its full-scale invasion of Ukraine in 2022 illustrate the use of force against the territorial integrity of a State.[8]  The United States and United Kingdom justified their invasion of Iraq in 2003 on the disputed ground that earlier Security Council resolutions authorised the use of force. Removing the government of Iraq was not an independent legal basis under the Charter.[9]  The UN Charter also notably prohibits not only the use of force however, but also its threatened use, but it can be seen that many States continue to threaten the use of force, and even nuclear force against other States in the modern world.  For example, in 2017, the Democratic People’s Republic of Korea (North Korea) and the United States engaged in a seemingly “tit-for-tat” nuclear threat or standoff.  In particular, North Korea threatened that it could strike the US mainland with nuclear missiles and tested ballistic missiles in the Pacific region (including overflights of Japan), whilst the President of the United States, Donald Trump, said in a speech at the United Nations that the United States would “totally destroy” North Korea if forced to defend itself or its allies. He did not specify nuclear weapons.[10]

It is submitted that many of these threats and uses of force are justified by States on the grounds of self-defence and that this has been made simpler for States because the Charter itself does not specifically cover whether or not the right to self-defence under international law also includes a right to use force before an armed attack occurs.  The legality of this threat will now be considered.

The Legality of the Threat of the Use of Force or Use of Force in Modern International Law and the “Bush Doctrine”

As stated, there has long been disagreement between international lawyers as to whether the right of self-defence under Article 51 UN Charter extends to situations where States seek to pre-emptively defend themselves from an attack or not.  The ICJ in the Nicaragua judgment considered self-defence against an “armed attack” that had already occurred and expressly left open the question of a response to an imminent attack.[11]  In Armed Activities on the Territory of the Congo[12], the ICJ rejected Uganda’s claim of self-defence against the Democratic Republic of the Congo (DRC). The attacks by armed groups were not attributable to the DRC, and the Court left open when such attacks might themselves justify self-defence.[13]  Dissenting in Nicaragua, Judge Schwebel argued that Article 51 should not be read as if it said “if, and only if, an armed attack occurs”.[14]  Instead, some States have argued that the right to self-defence in international law can also extend to anticipatory self-defence against an imminent attack, as they understand the customary law of the pre-Charter period.  This argument appears to be based on the wording of Article 51 which suggests that the right to self-defence in the Charter is simply a preservation and express re-affirmation of the existing position of customary international law, which therefore survives the Charters transposition of it into treaty.[15]  After 9/11, President George W. Bush advocated pre-emptive action even where the time and place of an attack were uncertain. The United States invoked self-defence in Afghanistan in response to the attacks of 11 September 2001. In Iraq it relied on Security Council resolutions.[16]  The “Caroline formula” required a necessity for self-defence so immediate that there was no other means or time to deliberate, and a response proportionate to that necessity. This is distinct from preventive force against a more remote danger.[17]  The ICJ recognised necessity and proportionality as customary requirements of self-defence in its Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons. Possession of a nuclear arsenal may indicate a readiness to use it, but whether that amounts to an unlawful threat depends on whether the use of force envisaged would itself be unlawful.[18]  The Court held that the threat or use of nuclear weapons would generally be contrary to the law of armed conflict. It could not decide whether either would be lawful in an extreme case of self-defence in which a State’s survival was at stake.[19]   The ICJ’s opinion therefore gives neither North Korea nor the United States a general right to make the threats discussed above. Since 2021 the Treaty on the Prohibition of Nuclear Weapons has expressly prohibited its parties from using or threatening to use nuclear weapons. Neither State is a party. Some States claim a right to act before an attack occurs, but those claims do not establish that preventive force has been accepted as lawful.[20]  Such claims may allow States to mask their territorial or political ambitions with a guise of legality.[21]  This is submitted to be something which the UN Charter was established specifically to prevent, and it may well be that acceptance of a broad right of preventive self-defence would pose an existential threat to the continued utility of Article 2(4) and the general prohibition of force under the UN Charter as a whole.[22]

Conclusion

In summary, State practice after 9/11 has not established a general right to use force against a merely possible future attack. Invoking self-defence to justify force shows that States still recognise the prohibition, even where their conduct breaches it. It can nevertheless be argued that broad claims of pre-emptive self-defence pose a real threat to the ongoing survival and efficacy of Article 2(4) UN Charter itself, and it might well be suggested that a better position would be for the ICJ to seek to prohibit the use or threat of force more clearly by tightening significantly the control over the use of pre-emptive force in the future.

Bibliography

Table of Cases

Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons [1996] ICJ Rep 226

Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v Uganda) [2005] ICJ Rep 168

Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) [1986] ICJ Rep 14

Table of Legislation

Charter of the United Nations 1945

Treaty on the Prohibition of Nuclear Weapons 2017, art 1(1)(d)

Secondary Sources

Arend AC, ‘International Law and the Preemptive Use of Military Force’ [2003] 26 The Washington Quarterly 89

Borger J, ‘Donald Trump Threatens to ‘Totally Destroy’ North Korea in UN Speech’ The Guardian, 19 September 2017, available online at; https://www.theguardian.com/us-news/2017/sep/19/donald-trump-threatens-totally-destroy-north-korea-un-speech accessed on 10 June 2018

Crawford J, Brownlie’s Principles of Public International Law (8^th edn OUP 2012)

Crowcroft R, ‘Rising to the Challenge? The State Since 9/11’ in Rachel Utley (ed), 9/11 Ten Years After: Perspectives and Problems (1^st edn Routledge 2016)

Gray C, International Law and the Use of Force (4^th edn OUP 2018)

Gray C, ‘The Use of Force and the International Legal Order’ in Malcolm Evans (ed), International Law (4^th edn OUP 2014)

Green J, Grimal F, ‘The Threat of Force as an Action in Self-Defense Under International Law’ [2011] 44 Vanderbilt Journal of Transnational Law 285

Helal M ‘Of Fire and Fury: The Threat of Force and the Korean Missile Crisis’ [2017] Opinio Juris, August 30 2017, available online at; http://opiniojuris.org/2017/08/30/of-fire-and-fury-the-threat-of-force-and-the-korean-missile-crisis/ accessed on 11 June 2018

Maogoto J, ‘Rushing to Break the Law? ‘The Bush Doctrine’ of Pre-Emptive Strikes and the UN Charter Regime on the Use of Force’ [2003] 7 UWSLawRw 1

McGuinness M, ‘Case Concerning Armed Activities on the Territory of the Congo: The ICJ Finds Uganda Acted Unlawfully and Orders Reparations’ [2006] 10 ASIL [1] 9

Simpson G, ‘Law and Force in the Twenty-First Century’ in David Armstrong (ed), Routledge Handbook of International Law (1^st edn Routledge 2009)

Wilson G, The United Nations and Collective Security (1^st edn Routledge 2014)