War, peace, right and wrong

Coverage of the recent discussions between Israeli Prime Minister Benjamin Netanyahu and US President Barak Obama has heightened talk about a stike against Iran, but the legal position is far from clear.

Israel’s apparent willingness to use force against Iran appears to be based on the notion of ’pre-emptive’ or ’anticipatory’ self-defence in international law.  Obama’s position is that a diplomatic solution is plausible, but force may be appropriate if necessary to defend the US and its interests.  

Behind the political posturing and debate lies a complex array of public international law issues. The starting point is the UN Charter and its general prohibition on the use of force (Article 2(4)).

The charter provides for two exceptions to this.  First, the UN Security Council may authorise the use of force (Article 42).  Second, states may use force in individual or collective self-defence if an “armed attack ­occurs” against a member of the UN (Article 51). The charter is, therefore, worded narrowly, and does not ­permit pre-emptive self-defence.

However, customary international law does provide for a limited right of pre-emptive self-defence. Specifically, the ’Caroline doctrine’ provides that an armed attack is appropriate only if there is a “necessity of self-­defence, instant, overwhelming, and leaving no choice of means, and no moment for deliberation”. The origin of this rule predates the UN Charter by over 100 years. This has opened the door to debate on the relationship between the norms and particularly whether the charter has displaced it.  

The relationship between treaty law, customary law and other sources of international law is complex and developing continually . Further, it is not limited to matters of foreign policy. Similar issues are arising in the field of international arbitration, particularly with respect to the relationship between bilateral investment treaties and customary international law. Domestically too, the courts are increasingly being asked to consider matters with a public international law element.  

By its nature, customary law is fluid. States need to be cautious when they purport to extend an existing principle.  Indeed, the line between attempting to extend a principle and breaching it is a fine one. This balance and the way the UN resolution 1441 on Iraq was invoked by the UK and US explains the caution of the Security Council in its approach to Libya and the situation in Syria.

In the UK, all three branches of government need to be mindful of what they say and do because their actions may have implications for the development of international law, particularly the development of ­customary international law.

Which brings us back to Iran. At a minimum, it can be said that any ­pre-emptive action in self-defence at international law requires an imminent threat.

t is difficult to see one within the scope of the Caroline ­doctrine and no armed attack within the scope of Article 51 appears to have occurred. For now, multilateral diplomacy may be the best approach Whatever happens, it is certain that, as the situation develops, the rhetoric will increasingly be framed in terms of international law, as attempts are made to justify whatever course of action is decided upon.

Baker & McKenzie associate Marty Montague assisted with this article