International Law and the Use of Force (LAWS70078)

The questions that arise from the use of force are amongst the most controversial both in international law and international relations. Different states, civil society and international lawyers have held over time diverse opinions about the legality and the legitimacy of events such as Russia’s invasion of Ukraine in 2022, the bombing of Iraq and Syria (by the US, UK, France, Australia and others) in the war against the ‘Islamic State’ and affiliates, the use of drone strikes globally in the ‘War on Terror’ since 2001, the exercise of the 'responsibility to protect’ by the ‘international community’ in Libya in 2011 and the 2003 invasion of Iraq, as well as debates over the possibility of a 'pre-emptive strike’ against North Korea or Iran. The question of what amounts to ‘force’ has also been contested by States since at least 1945, and the emergence of new technologies of warfare have reinvigorated these debates. Finally, the question of what to do about the unlawful use of force (including criminal and economic sanctions) has been the focus of renewed attention since Russia’s invasion of Ukraine and annexation of Crimea.

This subject provides a doctrinal, theoretical, and historical account of the relationship between international law and war that is centered on a wide range of case studies. On the one hand, we will focus on major contemporary debates about the legal regime established since the promulgation of the UN Charter in 1945. We will examine the specific arguments states and international organisations (such as the UN, NATO, the European Union or the African Union) have used in order to justify the resort to force, and the responses of states, international organisations, courts and other groups (especially those at the receiving end of this violence) to these justifications. For example, this subject will consider questions such as the legality of 'humanitarian intervention’, the possibility of lawfully launching 'pre-emptive strikes’ against a perceived threat, whether a state can invoke its right to self-defence against non-state actors, the use of nuclear weapons, targeted killing and the authority of the UN Security Council to authorise violence. On the other hand, this subject invites students to think contextually, historically and critically about these debates. We will discuss both earlier legal regimes pertaining to war (for example, that of the League of Nations) as well as arguments about the radical transformation of the relevant law since the turn of the century and the ‘War on Terror’. We will also ask broader questions about the ways in which legitimate violence is allocated between different actors by international law and how this allocation shapes international and domestic politics.

Principal topics will include:

• Historical approaches to the legal regulation of the use of force (including the relationship between the jus ad bellum and the jus in bello)
• The concept of 'force’ and exclusion from legal regulation of economic or political coercion
• Scope of the general prohibition on the use of military force in Article 2(4) of the UN Charter
• UN Charter framework for collective security and resort to force
• Scope of the right of self-defence, including anticipatory or collective self-defence
• Right to rescue nationals in foreign territory and right of humanitarian intervention
• Case studies on legality of the Russian invasion of Ukraine, the NATO bombing in Kosovo, Coalition of the Willing intervention in Iraq and the global ‘War on Terror’.
• The development and prosecution of the crime of aggression