E-mail this
Print Article

The Unlawful War Against Iraq — The Doctrine of Anticipatory Self-Defense Examined Under International Law*
by Saurabh Mishra & Sarvesh Singh

Cite as : (2003) PL WebJour 7


The centrepiece of the "National Security Strategy" President Bush unveiled on 20-9-2002 is the doctrine of pre-emptive military intervention—"We will not hesitate to act alone, if necessary, to exercise our right of self-defense by acting pre-emptively." The President had stated the doctrine earlier in an address to West Point graduates—"America must act against the terrible threats before they're fully formed," that is, use military force against any country that possesses weapons of mass destruction (WMD) and poses a threat to the United States.

The events of September 11 and the subsequent military response by the United States and its allies, and more importantly, the clear intention of the United States to attack Iraq raise some difficult issues in international law relating to self-defense, generally, and anticipatory self-defense, particularly. With the increase in terrorism, proliferation of weapons of mass destruction (WMD), border disputes and ethnic unrest, it is becoming increasingly ambiguous when a nation may lawfully resort to the use of armed force for its self-defense and the defense of other nations. Article 51 of the United Nations Charter attempts to codify the circumstances in which a nation may act in self-defense. Despite the express language of Article 51, much debate has taken place concerning the meaning of this article, when the right to act in self-defense accrues, and, perhaps more important, when it ceases.

The primary objective of this article is to explain that such a view of the United States relating to military strikes, in the disguise of "anticipatory self-defense" as evinced by the abovementioned "National Security Strategy" is totally iniquitous and completely in contravention of the well-established principles of international law. The article briefly reviews the UN Charter and the existing international law principles on a nation's right to resort to military strikes in self-defense. Lastly, the legality and propriety of the United States' contemplated unilateral military strikes against Iraq are tested within the parameters of existing international law on anticipatory self-defense.

Historical background

The right of anticipatory self-defense by forestalling an attack is well established in classical international law. In 1625, Hugo Grotius in The Law of War and Peace indicated that self-defense is to be permitted not only after an attack has already been suffered, but also in advance, where "... the deed may be anticipated". He further said: "It be lawful to kill him who is preparing to kill...." Similarly, in his famous text of 1758 known as The Law of Nations, Emmerich de Vattel affirms that "the safest plan is to prevent evil," and that to do so a nation may even "anticipate the other's design ...".

Where it is understood as "anticipatory self-defense", the customary right to pre-empt has its modern origins in what is known as the "Caroline" incident. In 1837, during the revolt in Canada against the British, a ship named The Caroline would periodically sail from US territory into Canada. It would reinforce and supply the rebels and then return to the United States. To put an end to this, British forces entered the United States, seized The Caroline and destroyed it, killing two US citizens. Upon receiving protests from the United States, the British claimed they had acted lawfully in self-defense.

In an exchange of letters with the British Government, Secretary of State Daniel Webster outlined what he believed were the conditions for a proper claim of self-defense. He stated that there "must be a necessity of self-defense, instant and overwhelming, leaving no choice of means and no moment for deliberation". He further argued that the act should involve "nothing unreasonable or excessive, since the act justified by the necessity of self-defense must be limited by that necessity and kept clearly within it".1 While never admitting culpability, the British apologized to the United States for the incident. Secretary Webster's Caroline criteria, described in the literature as those of "necessity" and "proportionality", continue to form the basis for analysis of the right of self-defense.2

"Necessity"3 is the most important precondition to the legitimate use of military force in self-defense. The International Law Commission has defined the term "state of necessity" as being:

The situation of a State whose sole means of safeguarding an essential interest threatened by an imminent and grave peril is to adopt conduct not in conformity with what is required of it by an international obligation to another State.4

In determining whether the use of military force is necessary, many factors must be carefully balanced. These factors include the nature of the coercion being applied by the aggressor State, the aggressor State's relative size and power, the nature of the aggressor's objectives and the consequences if those objectives are achieved. The target State makes the initial determination of the necessity of using military force in self-defense.

"Proportionality"5 is the requirement that the use of force or coercion be limited in intensity and magnitude to what is reasonably necessary promptly to secure the permissible objectives of self-defense. As the purpose of self-defense is to preserve the status quo, proportionality requires that military action ceases once the danger has been eliminated.6

Despite widespread reference to the Caroline factors, they have not been accepted without criticism. Many argue that these criteria are too restrictive, having been written in an era when an enemy literally had to be massed on the border to be a threat. With nuclear weapons and rapid delivery techniques, the requirement that no action be taken until "force be overwhelming, leaving no choice of means and no moment for deliberation" is seen by some commentators as unrealistic in today's world. Nonetheless, the Caroline factors continue to be relied upon in the analysis of potential self-defense situations.

Anticipatory self-defense under the United Nations Charter

The United Nations Charter recognizes the use of military force as lawful in only two instances, either as part of a United Nations' authorized military operation to restore the peace under Article 42 or for self-defense under Article 51. Article 51 provides:

Nothing in the present Charter shall impair the inherent right of individual or collective self-defense 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 the right of self-defense 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.

Despite the seemingly clear language of this article, considerable controversy surrounds the extent to which a member may take action in self-defense under the Charter. Many international law scholars argue that the customary international law doctrine of self-defense, as developed from the Caroline case, survives under the Charter. These scholars believe that the Charter was not intended to restrict the right of a nation to take defensive action in any material way.

Others argue that while the right to self-defense exists in the customary international law, each member of the United Nations, by adopting the Charter, has waived its rights to those aspects of self-defense that are not specifically permitted under Article 51. They reason that the United Nations was established to create order and that reliance on the customary international law would be counterproductive to that goal. While the majority of the experts in the field hold the opinion that the right of self-defense remains unimpaired under the Charter, this dispute remains largely unresolved.

The most intense debate concerning the right to act in self-defense under the Charter focuses on the right of a nation to act in self-defense in anticipation of an armed attack. There is little question that before the Charter, a right to act in self-defense, as recognized by the customary international law, included the right to act in anticipatory self-defense. Article 51 with its language "if an armed attack occurs", has been seen by some commentators as restricting a nation's ability to lawfully invoke that right.7 Others believe that no such limitation was intended and that the right to act in anticipation of an attack remains intact.8 The main arguments of each position are briefly outlined below.

Restrictivist view

According to this minority view, member States have only those rights which are affirmatively granted by the Charter. One such right permits actions in self-defense only once an armed attack occurs. Two policy considerations are advanced to support this position. First, determining whether an armed attack is imminent is extremely difficult. An error in calculation could lead a militarily powerful nation to start a war of massive proportions based on the mistaken belief that it was about to be attacked. Second, anticipatory self-defense is grounded in customary international law that provides no clear guidelines for its use. In the restrictivist view, the conditions in which such law may be relied upon are too vague to be of much help for the decision-makers. Even a large number of States, from all parts of the world, said that anticipatory self-defense was always contrary to international law.9

Expansivist view

According to the predominant view, to which the United States subscribes, Article 51 permits anticipatory self-defense in response to an imminent armed attack. According to the propounders of this view the restrictive view is a marked departure from the customary international law and that such a departure should not be lightly presumed. They believe that since Article 51 does not unequivocally limit the right of self-defense, it should not be construed as eliminating the customary law right to use military force against a threatened attack.10

Limits of the right of anticipatory self-defense

Whether one favour the restrictivist or the expansivist view, it is evident from the above discussion and the development of law that the right of anticipatory self-defense is not an open-ended right. In the modern world, the State that employs force has to justify it before the court of world opinion. If a State claims that it is acting in self-defense, then it will have to produce evidence that its actions are both "necessary" and "proportionate". This will also depend on the circumstances, but will also depend on whether there was sufficient time for alternative courses of action to be adopted bearing in mind the overall duty under Articles 2(3) and 33 of resolving a dispute peacefully. As experience since 1945 indicates, when a State purports to act in self-defense the legitimacy of its action will have to be justified before the Security Council.11 It would seem from the debates on the Cuban Missile Crisis (1962), the Middle East War (1967) and the bombing of the Osarik Nuclear Reactor (1981), that any State seeking to defend preventive action bears a heavy onus probandi and would have to demonstrate that: *

an armed attack is launched, or is immediately threatened, against a State's territory or forces (and probably its nationals); *

there is an urgent necessity for defensive action against that attack; *

there is no practicable alternative to action in anticipatory self-defense, and in particular another State or other authority which has the legal powers to stop or prevent the infringement does not, or cannot, use them to that effect; *

the action taken by way of anticipatory self-defense is limited to what is necessary to stop or prevent the infringement i.e. to the needs of defense;12 and *

the response by way of anticipatory self-defense must be immediate.

Indeed, the concepts of "necessity" and "proportionality" are at the heart of self-defense under international law. The Court in Nicaragua v. USA13 stated that there was a "specific role whereby self-defense would warrant only measures which are proportional to the armed attack and necessary to respond to it, a rule will establish in customary international law" and in the advisory opinion it gave to the General Assembly on the Legality of the Threat or Use of Nuclear Weapons14, it first emphasized "the submission of the exercise of the right of self-defense to the conditions of 'necessity' and 'proportionality' is a rule of customary international law".

The Iraqi situation

The use of military force in national self-defense is a right long recognized by the international community. Under customary international law, nations are permitted to act in self-defense if there is a need to do so, and the extent of the military response is not disproportionate to the threat. An example of "anticipatory self-defense" is Israel's strike against an Iraqi nuclear reactor in 1981, to keep Iraq from developing a nuclear arsenal. However, the UN Security Council condemned the attack, because the threat to Israel, though foreseeable, was not "imminent", as there was time to try other measures. The same UN Security Council also rejected Israel's argument that its 1985 attack on PLO headquarters in Tunis was self-defense. The application of the basic law regarding anticipatory self-defense to the present US confrontation with Iraq is straightforward:

Firstly, the intended military operations by the United States against Iraq do not fulfil the criteria and requirements of the doctrine of anticipatory self-defense under the existing international customary law, as: *

There is no immediate or imminent threat of an attack. Iraq has neither attacked any State, nor is there any evidence that an attack by Iraq is imminent. Further, there is no claim or publicly disclosed evidence that Iraq is supplying weapons of mass destruction (WMD) to terrorists. *

The present situation does not require a necessary and urgent military invasion against Iraq. *

The military strikes against a prospective aggressor must be immediate with no room for deliberations. But the United States' intended military strikes against Iraq seem to be a well-deliberated and well-planned invasion, which is completely unlawful and illegal under international customary law. *

The other peaceful means of resolution of the dispute and disarmament of Iraq from the weapons of mass destruction (WMD) have not exhausted and the United Nations Weapons Inspectors have still not found any incriminating evidence against Iraq. *

With the establishment of the United Nations, whose goal is to establish a world order aimed at maintaining international peace and security, the extent of a nation's right to act in self-defense has clearly diminished. Earlier the Security Council authorized an armed response to Iraq's invasion of Kuwait in 1990, and then after the termination of hostilities required Iraq to end its missile and chemical, biological and nuclear weapons' programs. Thus, under Article 51, the UN Security Council has taken measures necessary to maintain international peace and security, and the right of self-defense against an armed attack, applicable until the Security Council has done so, is no longer in effect. While few would argue that the Security Council's assumption of responsibility precludes self-defense in response to a future attack by Iraq, it weighs heavily against attempts to extend the boundaries of self-defense to justify use of pre-emptive force by the United States and selected other States.

Secondly, the thesis of anticipatory self-defense is not a principle accepted completely and in entirety under the international law today because it is prone to arbitrary interpretation. The extent of the right to act in self-defense is not always clear and considerable debate continues over these issues. It is precisely this ambiguity regarding the interpretation and scope of right of anticipatory self-defense that allows the United States to adopt an interpretation of UN Security Council Resolution 1441 which has no legal existence and validity under the customary law. The interpretation of UN Security Council Resolution 1441, which the United States has adopted to resort to war, is that the Iraqi leadership is at "material breach" in compliance with UN Resolutions. But what constitutes a breach is something which has to be decided by the UN and the UN alone and is not subject to arbitrary interpretation by the United States or any other country.

Thirdly, we would like to emphasize that the existing international legal standards of anticipatory self-defense do not permit retaliation, as is the case of Iraq. Most scholars agree that there is a difference between retaliation and self-defense; it's not hard to see how retaliation can lead to a cycle of violence. It's harder to understand why "anticipatory self-defense" is prohibited. That's because many people do not appreciate that the legal definition of self-defense is much narrower than our intuitive conception. That "the best defense is a good offense" may be true in football and other sports, but it is not enshrined in international or domestic standards with regard to unlawful, illegal and unjust military strikes against a country. This would severely threaten the lives of thousands of innocent civilians, destabilize the peace and security of the region, collapse the world economies and would have far-reaching consequences on the environment.

Lastly, the contemplated unilateral action to be taken against Iraq with thousands of marines and war infrastructure moving in the Gulf profoundly signifies the United State's ulterior motives in the oil wealth of the Gulf rather than self-defense. The "Strategic Energy Policy Challenges for the 21st Century" report describes how America is facing the biggest energy crisis in its history. It is a document that fundamentally questions the motives behind the Bush administration's desire to take out Saddam Hussain and go to war with Iraq. It targets Saddam as a threat to American interests because of his control of Iraqi oilfields and recommends the use of "military intervention" as a means to fix the US energy crisis. Moreover, the President of the United States is trying to fulfil a personal vendetta against Saddam Hussain for his alleged conspiracy to assassinate George Bush Sr.


The existing customary international law relating to anticipatory self-defense has no room for dramatically expanding the concept of self-defense, as advocated in the Bush administration's September 2002 "National Security Strategy" to authorize pre-emptive strikes against States based on potential threats arising from possession or development of WMDs including chemical, biological, or nuclear weapons and links to terrorism. Such an expansion would destabilize the present system of restraints on use of force as given in the United Nations Charter. The Bush administration's reliance on the need for "regime change" in Iraq as a basis for use of force is barred by Article 2(4) of the UN Charter, which prohibits "the threat or use of force against the territorial integrity or political independence of any State".

Moreover, the existing customary international law relating to anticipatory self-defense is too ill-defined to provide any detailed guidance on the legality of the United States' military operations against Iraq. The various uncertainties highlighted by this proper suggest there is a real need for the International Law Commission to codify what exactly are the principles that apply to the doctrine of anticipatory self-defense. This need is underscored by the fact that the main check on the exercise of the right of anticipatory self-defense, the United Nations Security Council, is unlikely to function if one of its permanent members considers that military strikes are in national interest.

*   Students, IVth year, BA, LLB (Hons.), National Law Institute University, Bhopal. Return to Text

  1. Letter from Daniel Webster, Secretary of State, to Lord Ashburton, 6-8-1842 as quoted in B.E. Carter and P.R. Trimble, International Law (2nd Edn., Little Brown & Co.), p. 1289. Return to Text
  2. For a scholarly commentary, see T. Kearley, Raising The Caroline, 17 Wis. Int'l LJ 325, Summer, 1999. Return to Text
  3. See Judge Ago's Eighth Report on State Responsibility to the International Law Commission, where it was noted that the concept of necessity centred upon the availability of other means to halt the attack so that "the State attacked ... must not, in the particular circumstances, have had any means of halting the attack other than recourse to armed force"—Yearbook of the International Law Commission, 1980, Vol. II, Part 1, p. 69. Return to Text
  4. Yearbook of the International Law Commission, 1980, Vol. II, Part 2, p. 34. Return to Text
  5. Judge Ago noted that the correct relationship for proportionality was not between the conduct constituting the armed attack and the opposing conduct, but rather between the action taken in self-defense and the purpose of halting and repelling the armed attack, so that "the action needed to halt and repulse the attack may well have to assume dimensions proportionate to those of the attack suffered", ibid. p. 69. Return to Text
  6. For a general discussion of the requirement of proportionality, see J.G. Gaalam, Proportionality and Force in International Law, 87 AJIL 391, 1993. Return to Text
  7. Included among such writers are I. Brownlie, Y. Dinstein, L. Henkin and P. Jessup. Return to Text
  8. Included among such writers are J. Stone, W. O'Brien, D. Bowett and M. McDougal. Return to Text
  9. UN Security Council Res 487, 19-6-1981, UN Chronicle, 1981, Nos. 8, 5-9, 61-74, p. 68. Return to Text
  10. R.G. Maxon, Nature's Eldest Law: A Survey of a Nation's Right to Act in Self-Defense, Parameters, Autumn 1995, p. 59. Return to Text
  11. J. O'Brien, International Law (1st Edn., Cavendish), p. 683. Return to Text
  12. Oppenheim's International Law (9th Edn.,), p. 412. Return to Text
  13. ICJ Reports, 1986, pp. 14, 94, 103. Return to Text
  14. ICJ Reports, 1996, para 41. Return to Text
Search On Page:

Enter Search Word:

  Search Archives
  Search Case-Law
  Search Bookstore
  Search All

Archives of SCC Articles
  Subjectwise Listing of Articles
  Chronological Listing of Articles
  Articles Exclusively on the Internet
  More Articles...

Most Accessed Articles
Recent Articles