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Fighting a Losing Battle? Justifying the Iraq War under International Law

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About The Author

Keir Baker (Former Editor in Chief)

Keir is a Trainee Solicitor currently in the fourth and final seat of his training contract at a major US law firm. He is a law graduate from Selwyn College, University of Cambridge. Outside the law, Keir is an accomplished goalkeeper in both football and hockey, as well as a keen actor and pianist. He is a long-suffering supporter of Middlesbrough FC.

There is no avoiding war; it can only be postponed to the advantage of others.

Niccolo Machiavelli

With Sir John Chilcot soon to release his long-awaited report, the findings of which represent the culmination of his inquiry into the role of the UK government before and during the 2003 Iraq War, one of the major issues likely to be examined is the legality of the initial invasion under international law. Despite securing the fall of Saddam Hussein. the invasion has always proved controversial: it has been condemned by a significant number of countries, the heads of many major religions, as well as many high-profile figures and current serving politicians. As Noam Chomsky noted:

[S]ome international law specialists compare the invasion of Iraq to the “crimes against the peace” for which Nazi leaders were indicted at Nuremberg.

Opponents of the War had many potential arguments: they could oppose the conflict on pacifist grounds, be sceptical about the existence of weapons of mass destruction (WMDs) in Iraq, or voice now-vindicated worries about the potential for it to cause significant destabilisation in the region. Yet perhaps the most cited objection was the potential illegality of the invasion, with many feeling that any claims of legitimacy were fabricated or without sound basis.

This article will therefore seek to identify and examine potential legal justifications for the Iraq War under international law, concluding that there is a line of argument that prevents invading states – such as the UK and the USA – from being held legally responsible for what the late Charles Kennedy MP described as the ‘worst foreign-policy mistake since Suez.’

A Prohibition on the Use of Force

Under international law, any threat or use of force that deprives a state of the whole or part of its territory is prima facie illegal. Article 2(4) of the Charter of the United Nations 1945 holds that every member state ‘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.’ In the Nicaragua case, this was held by the ICJ to be a rule of customary international law and therefore binding upon non-member states too.

The scope of this prohibition is debated, yet the predominant view is to consider it broad. In the Corfu Channel case, the ICJ held that the definition of ‘territorial integrity’ is unrestricted in the sense that it is not confined to just annexation or permanent occupation, while in Eritrea v Ethiopia it was held that recourse to force violates the prohibition even when a state has a valid claim over the territory concerned. In fact, there are an extremely limited number of exceptions to the prohibition; at its most generous and most controversial, the list would total only four:

  • Intervention by Invitation
  • Humanitarian Intervention
  • Self-Defence
  • UN Security Council Authorisation

So far as legal justification of the Iraq War is concerned, it is only the latter three potential exceptions that are applicable. However, the invocation of all three would still be controversial in this context; it would require heavy straining of their ambits and/or raise questions as to whether such exceptions even exist at all.

Humanitarian Intervention

First advocated by the UK to justify no-fly zones over Iraq in 1991, the existence of an exception to the Article 2(4) prohibition on the grounds of humanitarian concerns is strongly debated. The controversy stems from the rigidity of the prohibition on the use of force and the protection from states from outside interference: in the Nicaragua case, the ICJ confirmed that there was no general right of intervention in support of the opposition to a government of a state, no matter how worthy the cause. Indeed, in DRC v Uganda, this was held to apply even in cases of civil war or where there had been a prior, illegal intervention by another state in support of the government.

While there are concerns about such a doctrine being used to justify pretextual rather than altruistic actions, there are valid arguments in favour of the existence of the exception. Indeed, this was recognised by all 191 UN Members when they agreed to the terns of the World Summit Outcome Document 2005, which contained the Responsibility to Protect doctrine – this holds that each individual state has the responsibility to protect its populations from crimes against humanity through appropriate and necessary means, and that the international community should help states to exercise this responsibility where they are unwilling or unable.

However, at the time of the Iraq War in 2003, the existence of the right to intervene on humanitarian grounds was rarely used and not widely accepted. For example, though in 1999 it functioned as the legal basis for the NATO air campaign in Kosovo, its invocation was condemned by many states including Russia and China. Unhelpfully, the Security Council gave it no explicit support nor explicit condemnation, choosing only to welcome the withdrawal of Yugoslav forces and deploying UN peacekeepers.

Furthermore, while there was evidence that Saddam Hussein had been responsible for the deaths of at least 250,000 Iraqis, the idea of humanitarian intervention was rarely cited to justify the invasion. It was rarely argued that the conflict was about preventing mass slaughter and any other war crimes; at the time, nothing in that sense was ongoing or imminent. Indeed, to use such a justification would be to strain any definition on humanitarian intervention to such an extent that would be damaging. As Human Rights Watch have observed, the prominence of the Iraq War gave it great power ‘to shape public perceptions of armed interventions said by their proponents to be justified on humanitarian grounds,’ meaning that it could breed ‘cynicism about the use of military force for humanitarian purposes’ which would be ‘devastating for people in need of future rescue.’



Article 51 of the Charter of the United Nations 1945 holds that ‘nothing in the Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a member state.’ Once a state has declared to the Security Council it was the victim of an armed attack, it can use force that is necessary and proportionate in retaliation. This requires, according to the ICJ in the Oil Platforms case, the responding state to adduce evidence to show that based on facts reasonably known at the time – the armed attack requires the response proposed.

In the Nicaragua case, the ICJ held that an armed attack sufficient to warrant self-defence includes both actions by regular armed forces and also the sending of armed groups which carry out acts of such gravity that they are comparable to attacks conducted by regular armed forces. In the Oil Platforms case, the ICJ held that the state must show it was the intended and specifically targeted victim of the attack, and the court refused to exclude the possibility that a single attack on a vessel or an accumulation of small attacks is sufficient. 

Under customary international law – which the ICJ held in the Nicaragua case exists concurrently to Article 51 – there is a wider right that might include the right to anticipatory self-defence, whereby a state may use force to prevent an imminent attack from another state. The right to anticipatory self-defence – outlined in the Caroline test – existed before the Charter of the United Nations 1945  but it is still fiercely debated as to whether Article 51 excluded it. Mary O’Connell, quoting Sir Humphrey Waldock, describes the orthodox view as holding that:

[A] state may “anticipate” self-defence…where there is convincing evidence not merely of threats and potential danger but of an attack being actually mounted.

Pre-Emptive Self-Defence

In the context of the Iraq War however, it was clear that no attack by Iraq on any member state was imminent – something more than a right to anticipatory self-defence was thus required. In a speech to the United Nations on the 12th September 2002, President George Bush outlined the concept of pre-emptive self-defence, whereby a state could intervene when necessary to prevent a presumed threat from fully materialising. Bush – creating in the process what has since been termed the ‘Bush Doctrine’ – argued that the US had a right to defend itself pre-emptively against a future possible attack, calling Saddam Hussein's regime as ‘a grave and gathering danger,’ on the grounds of Iraq’s persistent efforts to acquire weapons of mass destruction that it could potentially supply to terrorists such as Al-Qaeda.

However, the ‘Bush Doctrine’ has been almost universally vilified and offers no valid legal justification for the invasion of Iraq. There was justified concern about Iraq possessing WMDs, but – as reinforced by the Nuclear Weapons Advisory Opinion – mere possession of WMDs (even nuclear weapons) is not in itself a threat to use force under Article 2(4), nor an armed attack that can warrant the use of force in self-defence. When Israel bombed an Iraqi nuclear reactor in 1981 to prevent Saddam Hussein acquiring nuclear weapons, the Security Council unanimously condemned the bombing, finding it a ‘clear violation of the Charter of the United Nations 1945 and the norms of international conduct.’

Furthermore, permitting pre-emptive self-defence and giving states the discretion to judge when it can use force is fundamentally at odds with the much of the Charter, such as Article 24 of the Charter of the United Nations 1945’s investing in the Security Council the primary responsibility to authorise force. No state had the right to invade Iraq because of speculative concerns about its possible future actions.

The Valid Justification – UN Security Council Authorisation


The UN Security Council is a body of fifteen members made up of five permanent members and ten elected members. Under Article 24 of the Charter of the United Nations 1945, it has ‘the primary responsibility for the maintenance of international peace and security’ and has the power – under Articles 39, 41 and 42 – to determine ‘the existence of a threat to the peace, breach of the peace and act of aggression’ and order ‘measures not involving the use of armed force’ or ‘action by air, sea, or land forces… to maintain or restore international peace and security.’  

In the past, it has been involved in the placing of economic measures upon Rhodesia and South Africa in reaction to their Apartheid regimes and the imposing of sanctions on non-state entities such as the Taliban in Afghanistan. More pertinently to this article, in response to the Iraqi invasion of Kuwait in 1990, the Security Council used its Article 42 powers to create Security Council Resolution 678: this authorised states to use ‘all necessary means’ against Iraq ‘to restore international peace and security in the area.’ This was the basis of Operation Desert Storm, whereby a coalition of forces including Saudi Arabia, France, the UK and the USA liberated Kuwait from Iraqi forces and forced the Iraqi forces – who had been under the command of Saddam Hussein – to retreat back to Iraq. Operation Desert Storm was ended in 1991 by Security Council Resolution 687, which outlined the conditions for a ceasefire that included the imposition of obligations upon Iraq to eliminate any WMDs in its possession.

The ‘Revival’ Argument

It is the content of these resolutions which provides the legal justification for the Iraq War, for it ensures that the Security Council’s authorisation for the use of force against Iraq can be revived. Security Council Resolution 687 – nor any other subsequent resolution – did not terminate, but merely suspended Security Council Resolution 678. Therefore, a violation of Iraq's obligations concerning WMDs under Security Council Resolution 687 revives the authorisation to use force in Security Council Resolution 678, when – as it should be considered to be – the violation was sufficiently serious to undermine the basis of the ceasefire.

The validity of this justification – in the sense that Iraq had seriously violated its obligations – is reinforced by Security Council Resolution 1441, through which the Security Council stated in 2002 that Iraq was in material breach of conditions of the ceasefire concerning WMDs and other missiles and armaments outlined in Security Council Resolution 687. It is also reinforced by past practice: in December 1998, the US and UK launched Operation Desert Fox using the ‘revival’ argument in line with Security Council Resolution 1205, which similarly noted that Iraq had breached its obligations under the ceasefire.

This line of reasoning is controversial and not widely accepted. Jules Lobel and Michael Ratner have argued that acceptance of the ‘revival’ argument undermines the centrality of control over the authorisation of force accorded to the Security Council by Article 24 by allowing elements of the process to be invested in the judgment of states. Many – such as the late Tony Benn MP – have contended that nothing less than explicit authorisation will do. Furthermore, this justification requires close engagement with the language of Security Council Resolution 1441: evidence must thus be adduced that Iraq had failed to comply and cooperate with the material breach of conditions of the ceasefire subsequent to the making of that resolution. There is certainly scope to argue, as Elizabeth Wilmshurst noted when giving evidence to the Chilcot Inquiry, the existence of Security Council Resolution 1441 alone – no matter what is stated – was not enough, and a further decision by the Security Council was required.

However, these criticisms overlook that close engagement with the language of Security Council Resolution 1441 also demonstrates nothing which explicitly excludes the revival theory. As Carl Gardner has noted, key operating provisions – namely operating provisions 4, 12 and 13 – did nothing to invest in the Security Council alone the sole competence to act; the Security Council’s inaction does not preclude action by others. Furthermore, any interpretation of these operating provisions that does not lead to the conclusion that Iraq’s material breach and failure to take its final opportunity meant it was lawful to use force under Security Council Resolution 678 places far too much emphasis on ‘assessment’ and ‘consider’ in operating provisions 4 and 12, and empties ‘serious consequences’ in operating provision 13 of all practical meaning. Instead, as Jack Straw correctly observed in front of the Chilcot Inquiry, Security Council Resolution 1441 represents a compromise between the rejection of the immediate use of force and the outright authorisation sought by the US and the UK. Therefore, while rejecting its use in itself as a ground for force, Security Council Resolution 1441 required only further consideration by the Security Council: no further decision or resolution was required.

Therefore, when Dr David Kelly subsequently identified further evidence of a breach of the ceasefire conditions by Iraq, the Security Council’s lack of action did not prevent the US and the UK from having the right to intervene. The authorisation under Security Council Resolution 687 was suspended by Security Council Resolution 678; but on condition Iraq verifiably disarm. So when Security Council Resolution 678 was breach and thus no longer in operation, the authorisation granted by Security Council Resolution 687 to use ‘all necessary means’ against Iraq to ‘restore peace and security in the area’ was revived, thus providing the legal justification for the invasion.


The legality of the invasion of Iraq in 2003 is one of the most controversial and divisive questions of contemporary international law. A 2,500-word article can do no justice to the complexity of the debate and its various argument; indeed, some argue that it is unlikely that Sir John Chilcot’s report – described by Clare Short MP as ‘longer than the Harry Potter books put together’ – will be able to do sufficient justice to it either.

As has been discussed, the majority of potential justifications that could in theory be cited to counter claims of the Iraq War’s illegality should not be accepted. To use the concepts of humanitarian intervention and self-defence to try and justify the conflict is to strain the limits or fabricate the very existence of these exceptions to the Article 2(4) prohibition.

Undoubtedly, the Iraq War has been an unmitigated disaster. The failure of the invading forces to ensure stability in the region has resulted in the rise of ISIS and further volatility in the region. However – no matter how distasteful or wrongfully-motivated they believe the Iraq War was – those who have labelled Tony Blair and George Bush as war criminals must be prepared to accept that the ‘revival’ argument does offer scope for both to justify their actions under international law.

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Tagged: Armed Conflict, Human Rights, International Law

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