Use of Force and International Law General Treaty for the Renunciation of War, 1928/ Briand Kellog Pact ‘solemnly declare in the names of their respective peoples that they condemn recourse to war for the solution of international controversies, and renounce it, as an instrument of national policy in their relations with one another.’ Article 1.

‘agree that the settlement or solution of all disputes or conflicts of whatever nature or of whatever origin they may be, which may arise among them, shall never be sought except by pacific means.’ Article 2 Covenant of League of Nations – Articles Jus ad bellum Jus in bello

What about the use of force in the national context only? Article 2(4) of the UN Charter: ‘All 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.’ Economic coercion?

‘that it is unable to regard such action [economic coercion] on the economic plane as is here complained of as a breach of the customary-law principle of non- intervention.’ ICJ in Nicaragua Non-UN members?

The notions of "threat" and "use" of force under Article 2, paragraph 4, of the Charter stand together in the sense that if the use of force itself in a given case is illegal - for whatever reason - the threat to use such force will likewise be illegal. In short, if it is to be lawful, the declared readiness of a State to use force must be a use of force that is in conformity with the Charter. For the rest, no State - whether or not it defended the policy of deterrence - suggested to the Court that it would be lawful to threaten to use force if the use of force contemplated would be illegal. (ICJ advisory opinion Legality of the Threat or Use of Nuclear Weapons, para 47.

Guyana v Suriname Exceptions Self-defence Caroline Incident (USA and the UK) ‘necessity of self-defence, instant, overwhelming, leaving no choice of means, and no moment for deliberation.’ US Secretary of State

‘the act justified by the necessity of self-defence, must be limited by that necessity, and kept clearly within it.’ Article 51 of the UN Charter 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. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council…

Oil Platforms [Iran v USA] Dismissed defence for lack of evidence “In the case of individual self-defence, the exercise of this right is subject to the State concerned having been the victim of an armed attack"... The United States must also show that its actions were necessary and proportional to the armed attack made on it, and that the platforms were a legitimate military target open to attack in the exercise of self-defence

Provision of assistance to non-armed bodies [T]he Court does not believe that the concept of "armed attack" includes not only acts by armed bands where such acts occur on a significant scale but also assistance to rebels in the form of the provision of weapons or logistical or other support. Such assistance may be regarded as a threat or use of force, or amount to intervention in the internal or external affairs of other States. Nicaragua Merits, para 195.

Terror attack by non-state actor use of force? Pre-emptive attack? Response of other states when in October 2001, the USA and UK launched air strikes against Afghanistan? Assuming condonation, customary international law has emerged?

Use of force to protect nationals abroad? For person, unclear. For property, illegal. Collective Self-defence Part of Article 51

‘It is also clear that it is the State which is the victim of an armed attack which must form and declare the view that it has been so attacked. There is no rule in customary international law permitting another State to exercise the right of collective self-defence on the basis of its own assessment of the situation. Where collective self-defence is invoked, it is to be expected that the State for whose benefit this right is used will have declared itself to be the victim of an armed attack.’ Nicaragua Merits, para 195.

‘[F]or one State to use force against another, on the ground that that State has committed a wrongful act of force against a third State, is regarded as lawful, by way of exception, only when the wrongful act provoking the response was an armed attack. Thus the lawfulness of the use of force by a State in response to a wrongful act of which it has not itself been the victim is not admitted when this wrongful act is not an armed attack.’ Nicaragua Merits, at para 211.

Intervention The Court... finds that no such general right of intervention, in support of an opposition within another State, exists in contemporary international law. The Court concludes that acts constituting a breach of the customary principle of non-intervention will also, if they directly or indirectly involve the use of force, constitute a breach of the principle of non-use of force in international relations. Nicaragua Merits, at para 209.

Humanitarian Intervention. NATO bombing in Kosovo? Declined to condemn by 12 to 3. Intervention for upholding or restoring democracy? Perils?

Chapter VII of the UN Charter Article 40 of the UN Charter provisional measures Article 41 of the UN Charter threat to the peace, breach of the peace, or act of aggression, it may proceed to take measures not amounting to use of armed force Dilemma with sanctions? Smart sanctions? Unilateral sanctions/ regional sanctions? Security Council may decide that the course of action under Article 41 would be inadequate and authorise the use of force under Article 42

Article 43 Duty of Members - armed forces, assistance, and facilities, including rights of passage Article 45 of the UN Charter ‘shall hold immediately available national air-force contingents for combined international enforcement action’ 47 of the UN Charter Military Staff Committee Chief of Staff of the permanent members In 1950 Security Council resolutions on Korea

In 1969, against the illegal racist regime of Southern Rhodesia, the UK was authorised to use force. Iraqi invasion of Kuwait in August 1990 Collective action of states Subsequent invasion of Iraq in March 2003 (Without UNSC resolution) controversial at best and illegal at worst