Most of the world is reacting to the United States current administration’s decision to kill a top Iranian general, with many transfixed by the prospects of World War III. The decision has been justified as an act of self-defence against imminent threats by Iran. The lawfulness of these actions is rightly a hotly contested issue.

Niall Ferguson, the author of an insightful biography on Henry Kissinger, reveals that the key to Kissinger’s journey from holocaust refugee to arguably America’s most influential statesman, is his ability to use history to his advantage. Kissinger subscribes to the philosophy that “one should study history in order to see why nations and men succeeded and why they failed”. His controversial foreign policy was no doubt shaped by what he witnessed in his native Europe, determined to prevent his new home from experiencing the same devastation.

Kissinger knows that what’s past is prologue and the future, while never repeating history exactly, will inevitably resemble it.

As US National Security Adviser, Kissinger defined peace quite simply as “averting disaster”. This is illustrated by Kissinger’s own writings on significant moments in history such as the West’s response to Hitler. He writes that if the democracies had moved against Hitler in 1936 we would not know today whether Hitler was a misunderstood nationalist or whether he was in fact a maniac. Democracies learnt that Hitler was in fact a maniac. Yes, they had certainty, but they paid for that certainty with millions of lives.

Similarly, post 9/11 the US defence policy is aimed at protecting itself from a recurrence of such a devastating terrorist attack. To ensure its safety, the US has used self-defence as justification to attack those that are suspected terrorists or perceived supporters of terrorism. One of the most morally and politically difficult areas of international law is the right to self-defence and whether this right includes the right to take anticipatory or pre-emptory action.

Anticipatory self-defence is the use of force by a state to repel an attacker before an actual attack has taken place. “Anticipatory” refers to the ability to foresee consequences of some future action and take measures aimed at preventing such action. What makes anticipatory self-defence complicated is what Ferguson calls the “problem of conjecture” — acting before one is certain to avoid potential, but uncertain consequences.

Section 2(4) of the United Nations Charter provides that “all Members shall refrain in their international relations from the threat or use of force against the territorial integrity and political independence of any state, or in any other manner inconsistent with the purposes of the United Nations”. However, this prohibition against the use of force is not absolute: one of the exceptions to the prohibition is self-defence.

Article 51 of the Charter provides that “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…”

If read plainly, Article 51 only prescribes the use of self-defence in the event of an armed attack against a member.

Many have argued, having reference to the drafting history of the Charter, that UN members inserted Article 51 not for the purpose of defining the individual right of self-defence, but for the purpose of clarifying the position in regard to collective understandings for mutual self-defence so that the Charter did not, therefore, affect the scope of the right of self-defence existing at that time in customary international law, which included the right to use force in anticipation of an imminent armed attack.

Therefore it is accepted that anticipatory self-defence is covered and regulated by Article 51. However, what is not clear are the parameters of anticipatory self-defence under international customary law.

Kissinger is of the view that “pre-emptive strategy involves an inherent dilemma: It is based on assumptions that cannot be proven when they are made. When the scope for action is greatest, knowledge is at a minimum. When knowledge is high, the scope for pre-emption has often disappeared”.

He succinctly highlights the complexities of pre-emptive self-defence when he says the key questions are: how is the threat to be defined, and through what institutions can resistance to it be implemented? If each nation claims the right to define its pre-emptive rights for itself, the absence of any rules would spell, as we have seen, international chaos, not international order. It is unfortunate that more often than not the war against terror is illegal as it occurs outside the boundaries of an armed conflict, outside of the UN Charter and the rule of law. What does or rather how should lawful anticipatory self-defence look?

Two restrictions apply where force is to be used in anticipatory self-defence of an imminent armed attack. First, military action should be used only as a last resort. It must be necessary to use force to deal with the particular threat that is faced. Second, the force used must be proportionate to the threat faced and must be limited to what is necessary. In addition, Article 51 of the Charter requires that if a state resorts to military action in self-defence, the measures it has taken must be immediately reported to the Security Council.

Academic Daniel Bethlehem formulated 16 principles, informed by his detailed discussions with experts who have operational experience in these matters, that he proposes should guide the exercise of anticipatory self-defence.

Of particular importance is Principle 10 which provides that a state may not take armed action in self-defence against a non-state actor in the territory of another state without the consent of that state. The requirement for consent does not operate in circumstances in which there is an applicable resolution of the UN Security Council authorising the use of armed force. Principle 14 provides that these principles are without prejudice to the application of the Charter, including applicable resolutions of the Security Council relating to the use of force, or of customary international law relevant to the use of force.

In my opinion, Principle 14 should mean that anticipatory self-defence must be conducted within a context where it is understood that the very aim of the UN Charter is to severely limit unilateral military action, and to place decisions on the use of force primarily with the Security Council. Any action that bypasses the Security Council must be deemed in violation of the Charter and therefore illegal.

As Matt Peterson of the Atlantic points out, what’s morally difficult about preventive violence is it that it involves great uncertainty about whether a possible terrorist really will commit harm. He states that part of the problem is in continuing to treat the “war on terror” as a military engagement. We should not think of this as war, these are murderers who are contemplating murder on a massive scale.

The US only has to look at its recent history in Iraq to understand the perils of unilateral action in the name of anticipatory self-defence unauthorised by the UN. The Bush administration feared that Saddam Hussein had weapons of mass destruction at risk of being shared with terrorists who could launch attacks against the US.

Donald Rumsfeld, Bush’s defence secretary, was asked if the rise of ISIS was ever even considered by the Bush administration as a “worst-case scenario”.

Rumsfeld inadvertently admitted that the information they had before them was never certain and “if it were a fact, it wouldn’t be called intelligence”. However, as it turned out, there were no weapons of mass destruction, just the costliest of conjectures.

Professor Noam Chomsky was asked how western leaders should react to the Paris attacks in 2015:

“It depends what they want to do. If you want to end it [terrorism], the first question you ask is: why did it take place? What were the immediate causes and what were the deeper roots? And then you try to address those. Where did all this come from? The invasion of Iraq?”

Understanding its history is indeed more important than military action because what’s past is indeed prologue and those who choose to ignore the past are condemned to repeat it. DM