1. International Law and the Use of Force (LG566) Topic 4: Self-Defence

2. What is Self-Defence?  The essence of self-defence is self help. Under certain conditions a State acting unilaterally or in association with other States may respond with lawful force to unlawful force.  Reliance on self-help as a remedy by States when their rights are violated is one of the hallmarks of international law.

3. History  The use of force in self-defence was a just cause during the ‘Just War’ period but lost importance during the ‘War as Fact’ period  Up to the point of the prohibition of war and the use of force, self-defence was not really a legal concept.  It was mainly just a political excuse for the use of force.

4. Customary Law  It is generally recognised that any use of force in self-defence is a legitimate use of force.  A body of customary has built up on self- defence - Caroline incident Necessity, proportionality, immediacy  This complements the law of the UN Charter on this topic. Does it over-ride it?

5. Conventional International Law and Self-defence  With the Covenant of the League of Nations, the Kellogg-Briand Pact and other international instruments prohibiting ‘war’ and ‘force’, the right to self-defence needed to be clarified.

6. Article 51 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 the 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 and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.'

7. Art. 51  Article 51 defines three important criteria for the use of force in self-defence, namely, the occurrence of an armed attack; the target (must be a 'member of the United Nations'); and a ‘reporting clause’.

8. ICJ on Self-Defence  Nicaragua v USA (Merits), ICJ Reports 1986, p. 14, para. 176, 199-200 Self-defence is part of customary law (necessity, proportionality) Self-defence is only exercisable by victim of an armed attack Collective self-defence is only lawful if assistance is requested

9. ICJ on Self-Defence  Advisory Opinion on the Legality or Use of Nuclear Weapons Case (1997) 35 ILM 809 and 1343 It is not possible to conclude that the use of nuclear weapons will always be illegal = in extremis, they may be used for self- defence. Proportionality, necessity

10. Self-Defence in Action  (a) Measures short of war On the spot reaction Defensive Armed Reprisals The Protection of National Abroad  (b) War

11. On the Spot Reaction  This is when a small-scale armed attack elicits at once and in situ the employment of counter-force by those under attack or present nearby (Dinstein)

12. Defensive Armed Reprisals  Armed reprisals are measures of counter-force ‘short of war’ undertaken by one State against another in response to an earlier violation of international law.  Armed reprisals are prohibited unless they qualify as an exercise of self- defence under Article 51 UN Charter.

13. Right to Protect Nationals Abroad  Sometimes dealt with under ‘Intervention’.  The right to use force to protect nationals may be justified on two grounds: the use of force to protect nationals is a form of self-defence; it is a right exempt from Article 2(4) because it is not (and does not compromise) 'territorial integrity or political independence'  Example: Israeli rescue mission in Uganda in 1976.

14. ‘War’  War as an act of self-defence denotes comprehensive use of counter-force in response to an armed attack (Dinstein)  3 conditions: Necessity Proportionality Immediacy

15. Necessity  When the use of force in self-defence is in response to a full-blown armed invasion, the issue of necessity usually becomes moot.  However, it becomes important when the use of force in self-defence is in response to an isolated incident.  Before using force in self-defence it must be proven that a reasonable settlement of the conflict in an amicable way is not attainable.

16. Proportionality  This concept relates to a symmetry or an approximation in scale and effects between the unlawful use of force and the use of force in self-defence.  Nuclear Weapons AO: ‘There is in neither customary nor conventional int’l law any comprehensive and universal prohibition of the threat or use of nuclear weapons as such.’

17. Immediacy  War may not be undertaken in self- defence long after an isolated armed attack.  However, there may be ‘justifiable delays’.

18. Collective Self-Defence  The right of collective self-defence has not been clearly defined.  The controversy is whether the right of collective self-defence is a collective exercise of individual rights of self-defence; or it is the exercise of a right by one or more states on behalf of the 'attacked' state  North Atlantic Treaty and other treaties look at collective self-defence as each party undertaking to defend every other party against attack.

19. Collective Self-Defence  In the 1986 Nicaragua Case, the ICJ said that ‘one state may not defend another state unless that other state claims to be (and is) the victim of an armed attack and asks the first state to defend it.’  In the case of the Gulf war, the US and its allies justified their use of force on this notion of collective self-defence.

20. Anticipatory Self-Defence  Anticipatory self-defence refers to defence against imminent armed attacks, that is, a pre- emptive strike before the enemy has actually attacked (strike first in anticipation of an attack in future).  Interpretation Problems.  But has been used by various States, e.g. Israel bombing Iraq in 1981 and US bombing Libya in 1986.