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CCADD International Conference at Bellem,

29th August to 2nd September 2003


The concept of ‘Preventive War’ – Old wine in a new wineskin.


By Hugh Beach


This essay addresses the question how far the concept of self-defence can be extended to cover precautionary action against a state on the grounds that it is expected to pose a threat, directly or by proxy, at some time in the future. It is an old question, given a new edge by the ending of the Cold War and the emergence of terrorism as a pervasive threat. The frame of reference is the existing body of International Law on resort to force - jus ad bellum – taken in conjunction with the precepts  of the Just War tradition[i].   We start with a basic presumption against military action of any kind, as set out in Article 4(2) of the Charter of the United Nations:


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. There are two key principles here: state sovereignty and non-intervention.  The question is under what circumstances can these be properly over-ridden?


Going back to the roots of Just War doctrine we find Aquinas saying: [ii] ‘a just cause is required namely that those who are attacked are attacked because they deserve it for some wrong they have done. So Augustine: “We usually describe a just war as one that avenges wrongs, that is, when a nation or state has to be punished either for refusing to make amends for outrages done by its subjects, or to restore what it has seized injuriously”’.


In modern terms this emerges as another key principle: the right of self-defence. Article 51 of the UN Charter says:

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.

It is clear that the term ‘inherent’ establishes that the right of self-defence has a basis in customary international law preceding the UN Charter and in no way dependent upon it. The Charter seeks to limit this right by insisting that it applies only until the Security Council has acted to re-establish peace and security. The fact that the Security Council often does no such thing gives this article a slightly utopian flavour.


Nonetheless, when Iraq invaded Kuwait in August 1990, it was precisely on the basis of this Article that the UN Security Council, by resolution 678 of 28th November, authorised member states to use force not only to secure Iraqi withdrawal from Kuwait but also to restore international peace and security in the area. Note that this latter clause was already stretching the notion of self-defence. Arguably it would have justified the allies in overthrowing the regime of Saddam Hussein there and then, but this issue was put on hold for a further twelve years.


The events of 11th September 2001 caused the concept to be stretched further. Next day the UNSC, by resolution 1368, taking its stand explicitly on the right of self-defence, declared the acts of the previous day ‘like any act of international terrorism [to be] a threat to international peace and security’. The Council then expressed its readiness ‘to take all necessary steps to respond’. (This is, of course, UN-speak for military action). This resolution was seen by the US government, quite reasonably, as justifying an attack on terrorist bases in any country or indeed on the government of such a country if it failed to prevent and punish such attacks. It was taken by the Americans to justify overthrowing the Taleban in Afghanistan on the grounds that that regime was being effectively funded and controlled by al’Qaeda. The resulting military campaign - Operation Enduring Freedom - began on 7th October and resulted in the fall of Kabul on 12th November.  The Security Council gave explicit endorsement to this action by a series of resolutions passed in the following weeks.[iii] Since the attack (of 11th September 2001) had already occurred (and was by no means the first of its kind) no element of pre-emption was involved and the American action fitted comfortably within Aquinas’ definition of Just Cause, ‘namely that those who are attacked are attacked because they deserve it for some wrong they have done’.


The notion of pre-emptive self-defence plainly goes beyond the terms of Just War tradition, but the Americans are correct in arguing that international law has long recognised that nations need not suffer an attack before they can legally take action to defend themselves against forces that present an imminent threat. In customary law the limits of this right are set out in the so-called Caroline criteria. In 1837 a group of Canadian rebels, based on Navy Island in Lake Ontario, were receiving arms, supplies and recruits from Buffalo, New York, carried by the Caroline, a private American ship. On 29th December a party of British marines crossed to US waters, rowed quietly up to the Caroline, set her alight and cut the anchor cable setting her adrift to float over Niagara falls.  She grounded short of the falls, but several of her crew were killed. The British Ambassador, Henry Fox defended the attack as an action of pre-emptive self-defence. The US Secretary of State, Daniel Webster, wrote in reply that a state has the right to act first in self defence only where ‘necessity of that self-defence is instant, overwhelming, and leaving no choice of means, and no moment for deliberation’.[iv] Since then the ‘necessity’ for any pre-emptive attack has been seen to rest upon the imminence of the threat and the proportionate nature of any response. The Arab-Israel war of 1967 was a case in point. On 18th May the Foreign Minister of the United Arab Republics (UAR), formally terminated the presence of the United Nations Emergency Force (UNEF) which since 1956 had provided a peace-keeping presence along the border between Israel and Egypt. Egypt then moved troops up to the border clearly implying an intention to attack Israel. Instead of waiting for this to take place Israel carried out a violent assault on Egyptian forces starting on 5th June. The Israeli forces quickly defeated the opposition and on 10th June a cease-fire was declared. This action was accompanied by a flurry of UN Security Council Resolutions. [v] While calling forcefully for a cease-fire none of them explicitly condemned Israel for acting pre-emptively. Finally UNSCR 242 of 22nd November 1967 called for the withdrawal of all Israeli forces from occupied territories. It could be said that the international community condoned Israel’s pre-emptive action on the grounds that the UAR had clearly signalled its imminent intention to attack, while rejecting as disproportionate Israel’s occupation of the whole of Sinai.


Recently we have seen the principle stretched much further. According to Geoff Hoon, British Secretary of Defence, the reason why Britain joined the American invasion of Iraq in March 2003 was ‘the threat, if not to the United Kingdom in the short term, then to our friends and allies in the Gulf region as well as to the wider stability of the world if we had not intervened to deal with weapons of mass destruction in the hands of a regime like Saddam Hussein. To that extent it was just’.[vi] Since, as Hoon says, there was no immediate threat to Britain, he was relying here on a doctrine of preventive military action to nip in the bud a possible future threat to international peace and security. The Americans have been quite explicit about this.  The National Security Strategy of the USA of September 2002 says, in discussing global terrorism: ‘we will not hesitate to act alone, if necessary, to exercise our right of self defence by acting pre-emptively against … terrorists, to prevent them from doing harm against our people and our country’[vii]. One cannot blame America for confronting a new reality head-on.  States do now face dangers that cannot be deterred when they are posed by shadowy terrorist networks with no nation or citizens to defend. Nor can they be ‘contained’ when unbalanced dictators armed with weapons of mass destruction (WMD) can deliver them on missiles or secretly provide them to terrorist allies. Such threats may indeed have to be tackled before they develop into actual armed attack.[viii] But great concern was aroused by the peremptory way this doctrine was announced and its blatant assumption of unique authority, ignoring the problems that would arise if other countries claimed a similar right. It was proclaimed in the context of a belief that the United States has an obligation to act, so as to create the conditions where freedom and democracy can flourish and to bring an end to conflict. This obligation applies globally and involves being prepared to use armed power, most notably American armed power, which therefore needs to be unchallengeable by any other nation. [ix] This statement seemed to claim for the USA carte blanche to attack any country it believed to be harbouring terrorists. But a closer reading suggests that the doctrine is much more narrowly focussed. ‘We must be prepared to stop rogue states and their terrorist clients before they are able to threaten or use WMD against the US and our allies and friends’[x].


So the Americans are now saying that the notion of imminent threat must take into account rogue states and terrorists relying on ‘acts of terror and potentially the use of WMD … that can be easily concealed, delivered covertly and used without warning. … The greater the threat, the greater is the risk of inaction - and the more compelling the case for taking anticipatory action to defend ourselves, even if uncertainty remains as to the time and place of the enemy’s attack’.[xi]  It has been pointed out that any right of anticipatory self-defence presupposes a right to act while action is still possible. If waiting for ‘imminence’ implies waiting until it is no longer possible to act effectively such a right would be illusory. Once a rogue state has achieved a serious capability with, say, nuclear weapons, effective action to eliminate that capability may have become impossible. Surprise use of such weapons could wreak catastrophic damage and the weapons themselves can be so successfully concealed that pre-emption is operationally impossible even if warning time were available. Hence a case exists that the right of self-defence includes a right to move against countries pursuing the acquisition of WMD with a high potential danger to oneself, while it is still feasible to do so.[xii] 


During the 1970s Iraq, with French assistance, was constructing a nuclear facility near Baghdad known as Osirak. Once Israeli intelligence had become convinced that Iraq intended to produce nuclear weapons there, it was decided to carry out a preventive strike. After meticulous planning the raid was carried out by F15 and F16 aircraft of the Israeli Air Force’s fighter corps. Shortly after 17:35 on June 7th 1981 the reactor was reduced to ruins. Israeli Prime Minister Menachem Begin described the attack as a ‘morally supreme act of national self-defence’ [xiii] The UN Security Council sat almost immediately to discuss the attack and on 19th June 1981 passed Resolution 487 which strongly condemned the attack and called for appropriate redress for the destruction Iraq had suffered. Members, the US included, were almost unanimous in condemning Israeli actions, several citing the Caroline case. The British representative, Sir Anthony Parsons, argued that the Israeli intervention amounted to a use of force which could find no place in international law or the UN Charter and which violated the sovereignty of Iraq. Yet with hindsight this was a classic instance of just such a military action as is now being justified as preventive self-defence. Perhaps the condemnation was rather too hasty. Osirak was never re-built, but over the next ten years, unknown to the outside world, Iraq set on foot a variety of other arrangements for manufacturing weapons grade nuclear material. None of these reached the point of actual production. But it is important to face the question, what would the situation been if Osirak had not been destroyed in 1981 and Iraq, at the time of its invasion of Kuwait in 1990, had possessed a few crude nuclear bombs? The eviction of Iraqi forces from Kuwait in 1991 would have been greatly complicated and prospective casualties so great that the attempt might never have been made. It is difficult not to conclude that the situation in the Gulf would by now be much worse than it is today.


An important aspect of the attack on Osirak is that it took place shortly before the reactor went critical, so as not to endanger the surrounding community. This raises the question of operational practicality in any pre-emptive operation. North Korea is a good case in point. Former Secretary of Defence William Perry has written that the US military could quickly destroy the plutonium-production reactor and the re-processing facility at Yongbyon without causing release of radioactive materials.  But US intelligence does not know where the plutonium extracted in 1991-2 has gone, still less where any resulting bombs are. Nor is it known with any accuracy where the incipient uranium enrichment facilities may be, still less where North Korea’s extensive chemical arsenal is held. So pre-emptive action against North Korea’s WMD is hardly an option. An even greater difficulty is the massive conventional force wielded by that country, which no conceivable means of attack could eliminate pre-emptively. The case for dealing with Iraq in 2003 rested in part on not allowing Iraq to reach the stage North Korea is at now. And the military option consisted not of striking at Iraq’s WMD capabilities directly but of replacing the regime as the only way of eliminating these capabilities with any confidence.[xiv]


But this argument raises in acute form the issues of capability and intention on the part of the rogue state. Does the country in question actually possess any weapons of mass destruction or at the very least necessary ingredients such as fissile materials or precursor chemicals? And if so, does it show any serious intention of transferring these things to terrorist clients?  Where Iraq was concerned the question remains open whether Saddam did possess chemical or biological weapons, or merely (as now seems likely) a vestigial programme that could be revived later. And the British Government, for one, has had little to say about intention. A dossier published in September 2002 [xv] said only that Saddam attached great importance to the possession of WMD that he regarded as vital to his goal of regional domination. Nothing was said about any intent to attack Britain or British interests or to pass on WMD technology to terrorists. Indeed the British Prime Minister told the House of Commons Liaison Committee on 21st January 2003 that he had no information that directly linked Iraq to the events of 11th September 2001. ‘I think that the justification for what we are doing in respect of Iraq has got to be made separately from any potential link with al-Qaeda’[xvi]. If Iraq’s purpose in acquiring WMD was simply regional influence with no clear link with terrorists then the case for attacking Iraq as part of the war on terror was weak indeed. Sir Adam Roberts has concluded that the impact of the doctrine of pre-emption on the Iraq crisis of 2002-3 was largely negative. The doctrine was not necessary for the war.[xvii]


The case for intervention in Iraq on humanitarian grounds is well known, and has been strengthened, if anything, by what we have since learned about torture, mass graves and the all the horrors of a police state. But the awkward fact is that the US and the UK were broadly supportive of Saddam while he was committing some of his worst atrocities - the war against Iran and his gassing of the Kurds. And other regimes, equally abusive, have been simply left to stew - Zimbabwe, Sudan, Congo - not to mention Chechnya and Tibet. Above all there is the question why now?


The strongest case for the legality of military action against Iraq this spring rested on the authority to use force given by the Security Council in 1990, which was never rescinded, and the continual flouting by Iraq of the terms of the 1991 cease-fire relating to inspections of their weapons programme - summed up in the unanimous UNSC Resolution 1441 of 8th November 2002 proclaiming Iraq to be in material breach of its obligations. This resolution gave Iraq ‘a final opportunity to comply with its disarmament obligations’. If Iraq failed, the Resolution promised ‘serious consequences’ and required the Security Council to convene immediately. Over the next five months Iraq did fail to satisfy the examiners. But at the meeting on 17th March the US and UK could not get a ‘second resolution’ authorising force. The question then was, did this failure trump the previous authorisation? The simple guiding principle must be that a resolution, once passed, remains in effect until there is a new resolution reversing it. This is the strongest case that can be made for the recent conquest of Iraq.[xviii] But it is not a happy one because the military campaign, to bring to an end the flouting of Security Council resolutions over many years, had to go ahead without specific endorsement at the point of action, because no majority for that action existed, and in the teeth of a promised veto.


There is a tragic irony here. Only by putting troops into the area was it possible to get the Iraqi government to readmit the weapons inspectors. It seems likely that in response to these moves Iraq had effectively rid itself of its offending weapons by early March. Yet Hans Blix, head of the UN inspectorate, in a formal statement to the Security Council on 7th March was only able to report that: ‘Iraq and its leadership have pursued a consistent strategy of concealing its weapons of mass destruction and deceiving inspectors in direct violation of its international obligations. Iraq’s weapons of mass destruction remain a direct and active threat to their neighbours and to the international community’.[xix] If the troops had gone home with the weapons question thus unresolved it would have meant a disastrous loss of face not only for the US and the UK but most importantly for the UN itself. The case was strong for a few months delay that could have given time for the UN inspectorate to come up with definite conclusions or, failing that, for the US to secure a ‘second resolution’ in the Security Council authorising the use of force. The arguments against such delay related to the onset of the hot weather in Iraq and the need to rotate the American troops involved. As matters have turned out some 150,000 American troops have had to sweat out the summer anyway, with no immediate prospects that the numbers can be reduced any time soon.


This essay has sought to show the limitations of pre-emption as a general policy. One might suspect that its salience in The National Security Strategy in September 2002 was little more than special pleading for the attack upon Iraq, already decided upon for rather different reasons. A whole raft of these pretexts has been suggested. Among the most plausible are the desire to tilt the Middle East on to a more progressive political track; to send a message that Western governments are not prepared to allow countries in the region to incubate Muslim fanatics and suicide bombers; to help resolve the Palestinian impasse; and to secure a dominant position for the US in the control of oil production. A more cynical view is that the US wanted to topple Saddam Hussain ‘because it was easy’. One thing however is clear, that the decision of the US to go to war, for whatever reason, had been taken long in advance. There are many indications of this. Secretary of Defence Donald Rumsfeld told the Senate Armed Services Committee on 9th July 2003 that no new information had become available that Iraq held WMD; ‘we acted because we saw the evidence in a dramatic new light –through the prism of our experience on 9/11’.[xx] His deputy, Paul Wolfowitz  has said ‘The truth is that for reasons that have a lot to do with the U.S. government bureaucracy we settled on the one issue that everyone could agree on which was weapons of mass destruction as the core reason’. [xxi] Most telling is the revelation, by Lieutenant General T. Michael Moseley, chief allied air commander in the Middle East, that air action to prepare the way for the attack had begun as early as mid 2002, under the pretext of reacting to Iraqi violations of the ‘no-fly’ zone in Southern Iraq.  He says that from June 2002 till the beginning of the war the US Air Force flew 21,7636 sorties and attacked 349 targets. These included cable repeater stations, key command centres, radars and other important military assets. These attacks were carried out, he says, precisely to lay the foundations for the military campaign against Iraq the following year.[xxii] A report for the US Joint Chiefs of Staff on lessons learned in the war is reported by the Washington Times to show that President Bush approved the overall war strategy in August 2002, eight months before the war began. [xxiii]


Michael Quinlan, well known as a somewhat hawkish Permanent Secretary in the British Ministry of Defence and, in retirement Director of the Ditchley Foundation with strong American ties, has recently summed up the British dilemma as follows:[xxiv]

‘[T]here is more and more ground for suspecting that for Mr. Blair, facing extremely difficult decisions, the real bottom line was not this or that justification for action against Saddam but the combination of three judgments: first, that Mr. Bush was intent upon war; second, that nothing Britain could do would ultimately deflect him; third, that British national interest required that in the end we go along.  Put another way, the question may have been not so much whether the arguments were good enough to warrant the huge step of starting a war as whether they were bad enough to warrant the huge step of breaking with the United States’. 





[i] An excellent summary is given in the Report issued by the US Roman Catholic Bishops in 1993 entitled ‘The Harvest of Justice is Sown in Peace’.

[ii] Summa Theologiae 2a2ae 40,1

[iii] UNSCR 1378 of 14th November 2001, UNSCR 1383 of 6th December 2001 and UNSCR 1386 of 20th December 2001.

[iv] See

[v] UNSCR 234 of 7th June 1967, UNSCR 235 of 9th June 1967, UNSCR of 11th June 1967 and UNSCR 237 of 14th June 1967.

[vi] Christian Socialist, Summer 2003, p. 4

[vii] The National Security Strategy of the United States of America, September 2002, Page 6. See

[viii] Adam Roberts. ‘Law and the use of armed force after Iraq’ in Survival, Summer 2003, p. 46

[ix] See the Remarks by President Bush at West Point on 1st June 2002,

[x] National Security Strategy.  op . cit.  p. 14

[xi] National Security Strategy.  op. cit. p. 15.

[xii] For an excellent discussion of this point see Walter B. Slocombe, ‘Force, Pre-emption and  Legitimacy’ in Survival,  Spring 2003, pp. 124,5.

[xiii] Michael McGinty, ‘That was the war  that was: international law, pre-emption and the Invasion of Iraq’, RUSI  Vol 148 No 3, June 2003, pp. 22,23.

[xiv] Walter B. Slocombe, op. cit. pp. 126-128. Gregory Treverton, ‘The Achilles’ heel of the Bush Doctrine’ International Herald Tribune, 25th August 2003, p. 6.

[xv] Iraq’s Weapons of Mass Destruction: The Assessment of the British Government. 28th September 2002. p. 4

[xvi] Michael McGinty, op. cit. p.24

[xvii] Adam Roberts, op. cit. p. 48. It is worth noting, however, that the foreign ministers of the European Union have recently accepted that member states may on occasions have to use military force to stop the spread of weapons of mass destruction. Meeting in Luxembourg on 16th June they approved a document entitled Basic Principles for a EU Strategy against Proliferation of Weapons of Mass Destruction. This included the following sentence: ‘When [non-military] measures have failed, coercive measures under Chapter VII of the UN Charter and international law (sanctions, selective or global, interception of shipments and, as appropriate, use of force) could be envisioned.’ See Tomas Valasek, ‘EU rethinks security stance’ in Jane’s Defence Weekly, 30th July, 2003. It is possible that an international consensus will emerge on this issue, not far different from the American point of view.                

[xviii] Adam Roberts, op. cit. pp. 42,43

[xix] See the useful summary of UNMOVIC’s so-called ‘Cluster Document’ delivered to the UN Security Council on 7th March 2003, at

[xx] Robin Cook, ‘Rumsfeld’s confidence trick’ International Herald Tribune 4th June 2003

[xxi] Deputy Secretary Wolfowitz Interview with Sam Tannenhaus, Vanity Fair,  Friday, May 9, 2003.

[xxii] Michael R. Gordon, ‘After the war: Preliminaries; US Air Raids in ’02 prepared for the War in Iraq. New York Times, 20th July 2003

[xxiii] International Herald Tribune,  4th September 2003, p. 3.

[xxiv] Michael Quinlan, ‘European Defence and the Western Alliance after Iraq’, a talk given at The Wyndham Place Charlemagne Trust, 17 July 2003.