What’s Wrong With Pre-emptive War?
It would be hard to overstate the importance of the present debate about the legitimacy of the Iraq War and of the legitimacy of the pre-emptive use of force in general.In this essay I will address only one aspect of this debate, the legitimacy of the principle of pre-emptive war, rather than the separate issue of its application to the case of .Such an inquiry is especially important given the multiple levels of confusion on several distinct issues in the current debate.It will be crucial in particular to clarify two of the most important areas of misunderstanding: first, the distinction between pre-emptive self-defense and preventive self-defense, and second the crucial distinction between pre-emptive (or preventive) force and pre-emptive self-defense.Without making these distinctions, it is likely that participants in this debate will be arguing at cross-purposes.
I. Pre-emptive versus Preventive Self-Defense
In order to investigate the question of pre-emptive war, we must first set out the nature of the right to self-defense under international law.It is beyond controversy that a nation has a right to defend itself when attacked, both under traditional Just War Doctrine and under the United Nations Charter (which calls it an ‘inherent right,’ i.e. presumably a natural right).There is however some controversy over the precise scope of the right to self-defense under Article 51 of the Charter.Does the right extend only to defense against an actual attack, as the Charter says, or is it implied that the right extends also to use invoke the self-defense right pre-emptively, where a threat is imminent but not yet actualized?A small minority of commentators argue that Article 51authorizes self-defense only against an actual attack – i.e. only after an attack has commenced.These are often called the “restrictionists”: for them it “would be unlawful to engage in any kind of preemptive actions” (id. p. 92).The rationale for the restrictive reading is that allowing nations to use force against imminent threats would open up too large a loophole for rogue nations.But limiting the use of force to actual attacks would impose a bright-line rule that would be hard to get around.Anyone can claim a threat is imminent, but there is usually clear evidence of an actual attack.
However, the restrictionist position has garnered little support.By far the dominant interpretation of international law has been that a nation is not required to wait until an actual attack, but may take steps to pre-emptively defend itself – so long as the attack is imminent.That is to say that pre-emptive self-defense is clearly permissible under international law, as part of the “inherent” right of self-defense.Whatever the actual intentions of the drafters of Article 51, it seems to be clearly the case that customary practice has made pre-emptive self-defense a fixed element in the current international law regime.There is, therefore, no substantial controversy over a nation’s right to pre-emptive self-defense against an imminent threat.
However, much of the confusion arises because the word ‘pre-emptive’ is sometimes used to mean the use of force against an imminent threat, and sometimes to mean the use of force where a threat is not even imminent.The problem seems to be a lack of agreement on the definition of key terms.Thus Mary Ellen O’Connor uses “preemptive” to mean the lack of imminence, i.e. what is more commonly called “preventive,” so for her pre-emptive force is illegitimate.She appears to use “anticipatory” to mean force against an imminent threat.Yoram Dinstein, in contrast, uses all three terms (pre-emptive, preventive, anticipatory) interchangeably as examples of impermissible use of force, but adopts the term “interceptive” to describe force that is legitimate.For Christine Gray, ‘anticipatory’ is but another name for ‘preemptive.’Mary Ellen O’Connell prefers the term ‘incipience’ as a substitute for arguments over pre-emption and prevention; Dinstein uses this “incipience” terminology as synonymous with “interceptive” (173), i.e. as permitting self-defense against what is usually called an imminent threat.
However, whatever the terminology one prefers, the questions at stake are relatively clear.First, does Article 51 materially change the scope of the traditional or ‘inherent’ right of national self-defense; and second, how far does that traditional right extend to the use of force to pre-empt an attack before it occurs?As we have seen, the wide consensus as to the first question is that the traditional right of self-defense remains even under Article 51.On the second question, again we seem to have a general consensus that a nation may use defensive force to pre-empt harm, so long as the attack is clearly imminent (even Dinstein allows for pre-emptive force in this sense, though he would reject the term ‘pre-emptive’).Thus what is ruled out is the use of purported self-defense as a justification for the use of force against a mere potential threat, where there is as yet no attack or even imminent attack.
To state this position more simply: under both contemporary practice and tradition, pre-emptive self-defense (self-defense against an imminent or actual attack) is permissible, whereas “preventive self-defense” – where there is not even an imminent threat -- is not permissible.It is thus the imminence requirement that is crucial in this debate, and that has been in place since Daniel Webster’s famous declaration in regards to the Caroline case that self-defense is permissible only if one is threatened by an immediate and overwhelming necessity, where there is ‘no moment for deliberation’. While Dinstein has called Webster’s formula ‘hyperbolic’ (212), still he agrees that the Caroline standard remains the criterion for self-defense by states (219).If the attack is not imminent, however, but merely a future possibility, then self-defense is not legitimate.It is then nothing radical at all to defend the right to use pre-emptive force.It is, however, a major shift to claim that a nation may resort to preventive self-defense, where there is not even an imminent threat as yet.And this, it is widely agreed, is not permissible.
Indeed, it may be said that the very idea of “preventive self-defense” is in fact oxymoronic and incoherent.Self-defense, it has been argued, is inherently pre-emptive; it is meant to head off harm before it occurs.Thus the very purpose of defensive force is to ward off an attack: that is what renders it ‘defensive.’In contrast, the use of force to prevent possible future threats is no longer defensive in the strict sense, but offensive.That is to say, it is no longer ‘defensive’ in nature.For the very idea of self-defense intrinsically involves action aimed at removing or pre-empting an immediate threat.As Suzanne Uniacke explain, self-defense is justified only against an immediate attack based on the “requirement of defensiveness: force is used in self-defence if it resists, repels, or wards off an immediate threat.”Kimberly Ferzan similarly defends the imminence requirement for both personal and national self-defense as the “defining aspect of self-defense: that self-defense is an action against a threat.”To argue for a new right of “preventive self-defense”, one that does away with the imminence requirement, does violence to the very concept of self-defense.Thus if the defenders of pre-emptive war mean by that a right to preventive self-defense, even before an attack becomes imminent, it is safe to say the argument must fail.There is no such thing as preventive self-defense.
However, this does not end the debate, for it is possible that this is not what the defenders of preventive war are suggesting.Two other possibilities suggest themselves.First, it is possible that the argument is not to eliminate the imminence requirement, but rather to revise and broaden it, thus permitting a form of self-defense that satisfies a more flexible interpretation of ‘imminence.’A second possibility is that the argument for pre-emptive war is rather a claim for the legitimacy of the use of force that goes beyond mere self-defense.This latter possibility will be treated in the next section.Here we consider the position of the Revisionists.
It is widely noted that the concept of ‘imminence’ cannot be as strictly applied to nations as to individuals.As Dinstein explains, a “State under attack cannot be expected to shift gear from peace to war instantaneously” (212), given the need for collective coordinated decisionmaking, mass mobilization, and so forth.To apply the Caroline standard literally – self-defense is justified only if there is “no moment for deliberation” -- would prevent any meaningful response by states, nor is it a standard we really want to apply (we want states to deliberate before striking out).This does not mean however, as some critics have argued, that the Caroline standard is not a genuine part of international law, or that it should be jettisoned.Quite the opposite: it has attained, as John Yoo recognizes, ‘mythic status’ as a foundational element in international law.It is just that Webster’s statement should be taken, as Dinstein suggests, as hyperbolic but nonetheless accurate insofar as it insists that immediacy is a primary requirement of self-defense.
Of course, the difficult with implicitly or explicitly rejecting the Caroline standard is twofold: first, it requires a radical rewriting of the international law of self-defense.Even more serious, if the Revisionist position turns out to be a way not of merely tinkering with the Imminence Requirement, but rather jettisoning it, then it is subject to the objection of incoherence: it can no longer be justified as defensive force, but is in need of some wholly new moral and legal basis.Note that this issue is not merely one of technical conformity with the law of self-defense, much less a merely conceptual issue about the ‘meaning’ of self-defense.It is a deeply moral question about the legitimacy of the use of force.The most universally recognized justification for the use of force in international law is that it is defensive.One ought to be quite wary of giving up this justification without serious attention to what the alternative will be.
It is of course possible to develop a genuine Revisionist account of the imminence requirement.As we have seen, it is widely accepted that the imminence requirement should be interpreted less strictly with regards to nations than with regard to individuals.Even more important, it seems equally uncontroversial that imminence is relative to circumstances, including both the nature of the threat and the capacity to defend against it (e.g. the nature of the delivery system, the detectability of the attack, the ability to take defensive measures against it).In the days when an attack required an actual cross-border invasion by a massive force, there would have been much more warning and therefore a much stricter standard of imminence.But when the threat is a nuclear weapon smuggled into the country inside a suitcase to be detonated by surreptitious terrorist agents, a judgment of imminence should be interpreted far more loosely.It is crucial, however, to retain the distinction between revising the imminence standard and getting rid of it altogether.
Not surprisingly, the very same ambiguity about the concept of imminence appears in the “Bush Doctrine” and its justification for pre-emptive force in the 2002 National Security Strategy document and elsewhere.The NSS argues explicitly for the traditional right of “pre-emptive” self-defense rather than preventive force:
The has long maintained the option of preemptive actions to counter a sufficient threat to our national security. 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. To forestall or prevent such hostile acts by our adversaries, the will, if necessary, act preemptively.
As we have seen, the crucial question is whether the imminence requirement is maintained.Here we get conflicting signals.In an interview on Meet the Press (), Bush explicitly rejected the imminence requirement: “I believe it is essential that when we see a threat, we deal with those threats before they become imminent.It’s too late if they become imminent.”In the same interview, he noted that thee State of the Union address pointedly described as presenting a “grave and gathering threat” but not an imminent one.One might therefore think that the Bush Doctrine dispensed with the imminence requirement.But that would be wrong.In fact, the NSS claims only to ‘adapt’ rather than reject imminence:
We must adapt the concept of imminent threat to the capabilities and objectives of today’s adversaries.Rogue states and terrorists do not seek to attack us using conventional means.They know such attacks would fail.Instead, they rely on acts of terror and, potentially, the use of weapons of mass destruction – weapons that can easily be concealed, delivered covertly, and used without warning.
The has long maintained the option of preemptive actions to counter a sufficient threat to our national security. 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. To forestall or prevent such hostile acts by our adversaries, the will, if necessary, act preemptively.
Furthermore, both White House Press Secretaries (Fleischer, McClellan) at different times indeed claimed that did indeed pose an imminent threat. Hence the enormous confusion about whether the imminence requirement is retained.Some commentators have argued that in fact the Bush Doctrine rejects imminence; others have made the opposite argument: that even when the Administration deliberately claimed that Iraq was a “grave and gathering threat,” it implied that it was an imminent one.What then is the Bush Pre-emption Doctrine?Does pre-emption mean self-defense against an imminent threat, or does it mean the use of preventive force before the threat becomes imminent? And what was the justification for the Iraq War: was there an imminent threat or not?
The question is crucial, for as I have argued, pre-emptive self-defense is a legitimate concept under traditional Just War Doctrine and current international law.But preventive self-defense – where there is no imminent threat – is not legitimate, or even coherent.And this is not, as President Bush suggested to Tim Russert, a mere matter of ‘word contests,’ but rather a crucial substantive question of law and morality.However, as we shall see in the next section, to rule out the idea of ‘preventive self-defense’ is not to reject the idea of preventive force even where there is no imminent threat.
II. Preventive Self-defense versus Preventive Use of Force
I have suggested that the very idea of preventive self-defense is extremely dubious morally and legally, indeed arguably oxymoronic.However, even if this is correct, that does not end the debate, for there is another closely related issue that is easily confused with the first.That is: while preventive self-defense is not a legitimate concept in the Just War tradition, the same does not hold for preventive force more generally.In the domestic case, self-defense is properly understood as an exception carved out from the “monopoly of force” that society holds.In general the citizen is not permitted too resort to force, as that is the province of the police.But where the individual is under an immediate threat, such that he cannot resort to society to protect him in time, he is permitted to use self-defense.Thus we see the origin of the imminence requirement: if the threat is not imminent, then the individual does not have an excuse for violating the societal monopoly on force.A citizen’s use of force is thus limited to self-defense precisely because of the societal monopoly on force.It does not, however, follow that society itself is limited to defensive force.Quite the opposite: the police power extends beyond the imminence requirement in both directions; society is entitled to punish past wrongdoings as well as prevent future harms.
The analogy at the international level holds: while signatories to the United Nations Charter cede the monopoly on the use of force to the Security Council, they explicitly reserve the ‘inherent’ right to act in self-defense, where there is an immediate threat.But it does not follow, of course, that the Security Council itself is limited to defensive action against imminent threats.For self-defense is only one form of the use of force.The United Nations itself may use force in ways that individual nations may not – and among these is the preventive use of force.Indeed, the UN Charter explicitly states as one of the purposes of the United Nations the “prevention and removal of threats to the peace” (Article 1; cf. Art. 2(5), Art. 50).Indeed, it is widely and plausibly assumed that, whatever the legitimacy of the United States’ decision to declare war on Iraq, the United Nations would have been within its rights to authorize just such preventive force against Iraq if it so decided, regardless of whether Iraq posed an ‘imminent’ threat.
But what about before the establishment of the United Nations regime?Were nations permitted to use preventive as well as pre-emptive force under Just War Doctrine?It is one of the great contemporary fallacies about the Just War Doctrine that the only traditional just cause for war is self-defense.Paul Ramsey labels this misconception the modern Aggressor-Defender model of war, under which the initiation of force is prohibited, and preventive war is “wholly unjustifiable under any circumstance.”In fact, this model reflects not the Just War tradition but the 20th century ideal of limited war, as reflected in the Kellogg-Briand Pact and the .Historically, the Just War tradition admitted of at least 3 distinct rationales for war: the prevention of injustice, the recompense of victims of past injustice, and the punishment of perpetrators of injustice.
It is clear that both tradition and contemporary international law do indeed permit the waging of preventive war, so long as it satisfies all other Just War principles and principles of law.Indeed, it would be exceedingly odd to insist that there is a universal moral duty not to prevent harm before it happens – especially since, as Grotius recognized, we grant the right to prevent harm in the domestic context.Further, there seem to be some clear historical examples where in retrospect preventive war would have been a good idea.The most commonly cited example is Nazi Germany’s illegal remilitarization of the in 1936. Why then has the use of preventive force been treated with such suspicion?One answer is concerns about necessity and proportionality.Where the threat is not yet even imminent, is it necessary or proportional to use force, especially the massive force involved in waging war, against a speculative future possibility?Can it be said that force is a last resort, where there are obviously other approaches available?The answer to these objections should be obvious however.The goal of preventing future harm does, as we have said, satisfy the ‘just cause’ requirement in Just War Doctrine.But just cause is only one of several distinct requirements, including necessity, proportionality, and last resort.Therefore it is no objection to bring up these other requirements, for they are independent of the issue of preventive force.The question before us is solely whether preventive force satisfies the just cause condition – a question we have answered in the affirmative.
A more serious concern about preventive war, however, is the great danger of its misuse.One of the motivations for the Aggressor-Defender Model was that it limited the justification for war to clear cases of invasion or aggression, where there is no doubt about the need for the use of force.In contrast, where there is a potential future threat, even the most well-intentioned decisionmakers will have great trouble assessing whether there is a sufficient future threat to justify war.And of course not every decisionmaker is so well-intentioned, and can easily claim some future potential threat as a justification for his aggression. the Great notoriously started three preventive wars against Catholic Austria, ordering his ministers to “cook up some legal nonsense” to justify his aggression.The problem of course is that a fundamental principle of Just War Doctrine is that war must be the response to a genuine wrong, even if that wrong has yet to happen.But preventive force raises particular concerns, since the wrong has not yet happened and may never happen.
However, even granting the seriousness of these concerns, it is important to recognize that the concerns expressed here are about the misuse of preventive force, and do not constitute rejections of preventive force itself.The real concern, of course, is that the more force is preventive rather than defensive (i.e. aimed at preventing potential future harm rather than actual present harm), the more it risks turning into its opposite: aggression against the innocent.These concerns call for the need for clear evidence of a genuine threat before justifying resort to force.The problem is a familiar one in the domestic context as well.We want police to proactively intervene to prevent crimes before they occur, thus we create categories of crime such as ‘attempt’ and ‘conspiracy’, which allow arrest and prosecution even where the underlying substantive crime was not committed.Yet at the same time, we express concern for the rights of the accused, since we cannot always be sure they whether they might have decided not to commit the crime after all (hence we distinguish a genuine attempt from ‘mere preparation’, which is not criminal).In domestic law enforcement, as in international law, we must struggle to find a balance: intervene too early, and we risk harming the innocent; intervene too late, and the harm is already done.But it must be insisted that, whatever the risks, the use of preventive force is and should continue to be a legitimate tool in both the domestic and the international context.Still, we must recognize the crucial restrictions on its use, including most significantly the ‘proper authority’ requirement of Just War Doctrine.
III. Preventive Force and the Proper Authority Requirement
We have argued that preventive force is a legitimate just cause both in Just War Doctrine and under the United Nations regime, of course subject to the other restrictions such as necessity and proportionality.But most important is the requirement that the use of preventive force is restricted to the proper authority.We need not delve into the complex question of who counted as a proper authority in Just War tradition, as the question is clearly settled by the United Nations Charter: only the Security Council has the authority to approve of the preventive use of force.Nations acting individually or collectively have only just cause for the use of force: self-defense against an imminent threat: and of course the only reason for the exception is that where the threat is not imminent, there is no opportunity to go to the Security Council for protection.This is of course a direct analogy to the domestic context, where the state has a monopoly on all uses of force besides self-defense, and preventive force is not allowed to individuals or groups.
One might see this idea of a monopoly of force as a response to the problem of abuse and manipulation of preventive force.To allow individuals to decide when there is a sufficient potential threat that requires preventive action now is to invite abuse.For it violates the fundamental principle of law that no one should be a judge in his own case.
Even the most well-intentioned actor will be prone to exaggerate the danger of future harm and the need for current action, as well as to judge his opponent’s conduct more harshly and his own conduct more generously.The public authority provides an objective, disinterested viewpoint with which to judge the necessity of force.Only where the attack is imminent do we permit an exception to this, for at least there is a bright line by which to judge the legitimacy of the resort to force.Indeed, the Charter requires that a nation exercising its right of self-defense immediately refer the matter to the Security Council for judgment as to the legitimacy of the resort to force.
It might seem then that the issue is settled: preventive force is not available to anyone other than the Security Council.However, there is yet another level of debate to be found here: whether the restrictions in the Charter are still valid and binding.We might call this the Unilateralist Argument.On this view, the limitation to self-defense under the U.N. Charter is predicated on the Security Council in fact being effective at protecting individual nations; no country would rationally cede its right to preventive force unless it had the assurance that it would be in its interest to do so.But if the Security Council proves to be unable or unwilling to use preventive force where necessary to protect an individual country, that country retains (or regains) its right to the broader use of force on its own.This in fact seems to be just the position of the NSS:
We will disrupt and destroy terrorist organizations by …defending the , the American people, and our interests at home and abroad by identifying and destroying the threat before it reaches our borders. While the will constantly strive to enlist the support of the international community, we will not hesitate to act alone, if necessary, to exercise our right of self defense by acting preemptively against such terrorists, to prevent them from doing harm against our people and our country.
Thus although this passage uses the language of pre-emption and self-defense, its underlying meaning seems to be rather one of preventive force (“identifying and destroying the threat before it reaches out borders”; “prevent them from doing harm”).
Where the international authority has failed to carry out its mandate of the use of preventive and punitive force, the right reverts to individual nations to do what is necessary to protect themselves.
Critics of this outlook, of course, argue that it is blatantly self-serving and a self-fulfilling prophecy as well.Every nation will be liberated to act on what it deems is its best interests, and the very idea of the international rule of law will disappear.And the nature of unilateral action raises the problem of judging one’s own cause – as for instance where the Bush Administration was able to see clear evidence of WMD’s in where other more disinterested judges did not.For all its faults, critics claim, the United Nations is the best system we have to avoid international anarchy, and while it is far from perfect, the alternative is much worse.Still, there is a genuine issue here to be debated: at what point does the international monopoly on force cease to be effective and therefore binding on individual nations?
IV. Assessing the Debate Over Pre-emptive War
My purpose in this essay is not to evaluate any of these arguments, adjudicating as to the status of the United Nations, or the legitimacy of unilateral action.Rather, the aim here is simply to articulate the various strands in the debate over the use of preventive force, for it is an unfortunate feature of the argument that these distinct strands are continually getting tangled together.The lack of standardized terminology is part of the problem: there is no clear distinction between preventive and preventive, or between defensive force and force more generally.But, I have tried to argue, the inconsistency in terminology reflects much deeper ideological divisions in law and morality over the legitimacy of force.In order to sort these out, we need to demand that opponents or proponents of ‘pre-emptive war’ identify just what their position is.
Hence, as we have seen, the National Security Strategy is multiply ambiguous on the key issues.Is it arguing for an expanded right of self-defense, or for a right to unilateral preventive force?Is it arguing for ‘adapting’ the imminence requirement as it claims, or is this an indirect way of rejecting imminence?Is it suggesting the United Nations does not have a monopoly on preventive force at present?The document is particularly (no doubt deliberately) ambiguous as to its view of the United Nations.
While it offers no direct criticism of UN, it gives no particular praise of it either, and the few times it is mentioned at all it is grouped together with other international organizations: thus the United States “is committed to lasting institutions like the United Nations, the World Trade Organization, the Organization of American States, and NATO as well as other longstanding alliances.”Furthermore, the document insists on a right to unilateral action: “we will not hesitate to act alone.”
However valuable such ambiguity may be from a political or legal perspective, it is the job of the scholar to insist on clarifying as far as possible the moral and legal basis for pre-emptive/preventive war.My aim in this essay is to engage in just such a clarification of the debate, though without attempting to resolve the issue either in general or specifically with respect to the Iraq War.Nonetheless we can state the key findings thus far:
1) the idea of ‘preventive self-defense’ where there is no imminent threat is incoherent and confused;
2) Imminence is an absolute requirement for a claim of self-defense, though there is an argument to be made that the imminence standard needs to be interpreted less strictly in regards to international conflicts, especially where there are weapons of mass destruction;
3) Contrary to the received wisdom, there is nothing intrinsically wrong with preventive war (or the preventive use of force more generally), though of course it is subject to important constraints (proportionality, necessity, etc.);
4) A crucial restriction on the use of preventive force is the Public Authority requirement.Under the U.N. Charter, the only body entitled to authorize preventive international force is the Security Council.
The current debate over pre-emptive war is thus, it seems, largely misguided.The central issue is not the legitimacy of pre-emptive war per se, but rather the status of the international law regime in place since the founding of the United Nations.Has the Security Council failed in its responsibility to exercise its authority to prevent threats to the peace?And if it has, are individual nations now permitted to take over that function, and protect themselves with pre-emptive use of force even where there is no imminent threat?The heart of the debate, it seems to me, is not the question of the legitimacy of pre-emptive/preventive force, but rather the question of the unilateral use of preventive force by nations acting without authorization from the Security Council.
 Anthony Arend, “International Law and the Preemptive Use of Military Force,” The Quarterly, Spring 2003; John Yoo, “Using Force,” 71 U. Chi. L. Rev. 729, 738 (Summer 2004).
North Korea tested a Hwasong-14 intercontinental ballistic missile on July 4, rushing closer to posing a major nuclear threat to the United States. Just a few weeks later, on July 28, the Kim Jong Un regime tested another ICBM, this time with a range that may include major cities in the continental U.S. To make matters more concerning, the Defense Intelligence Agency has said that North Korea might successfully arm an ICBM with a nuclear warhead as early as next year. And according to The Washington Post, U.S. analysts have concluded that Pyongyang has produced a miniaturized nuclear warhead that can fit inside its missiles.
In a recent Atlantic article, Mark Bowden examines U.S. options for responding to the North Korean nuclear threat. While all paths forward present significant challenges, Bowden writes, he strongly advocates against an anticipatory attack on the North. Meanwhile, the Trump administration has repeatedly said that it is keeping all options, including a militarystrike, on the table—a path that could potentially result in the greatest loss of life in conflict since World War II.
Suspending consideration of the strategic questions that would factor into the decision, how would the U.S. justify a pre-attack strike on North Korea under international law? And how would the rest of the world react?
History offers a relatively small sample of cases to provide guidance on these questions; states simply don’t strike their peers in the name of self-defense all that often. When they do, experts and politicians often debate the asserted justifications for years.
This post reviews several examples of pre-attack strikes taken by a variety of states asserting self-defense; examining the context, rationale and international response. These cases might offer insights into an impending decision on the North Korean question.
What kinds of strikes qualify as self-defense?
In her book chapter "Taming the Doctrine of Preemption" (contained in the "Oxford Handbook on the Use of Force in International Law"), University of Virginia Law scholar and Lawfare contributor Ashley Deeks provides helpful definitions of the three terms primarily used by scholars to discuss types of pre-attack self-defense: anticipatory, preemptive and preventive. Her definitions are adapted below.
- Anticipatory self-defense often corresponds with the standard established in the famous 1837 Caroline case, in which British soldiers in Canada crossed the Niagara River to attack and send over Niagara Falls the American steamship Caroline that was assisting Canadian rebels. The British asserted that they attacked in self-defense, but then-Secretary of State Daniel Webster wrote in correspondence with the British government in 1842 that the use of force prior to suffering an attack qualifies as legitimate self-defense only when the need to act is “instant, overwhelming, and leaving no choice of means, and no moment for deliberation.”
- Preemptive self-defense tends to have a longer time horizon. In this case, a state often views an opponent’s particular, tangible actions as almost certainly developing into an armed attack against it. While there may be some time before the opponent can launch the attack, the opponent’s actions indicate an attack is likely should developments continue.
- Preventive self-defense seeks to halt the development of a future threat, often without having precise information about where or when the attack might occur. States sometimes invoke preventive self-defense even without specific evidence of the opponent’s capacity or intent to attack. Many states often consider actions falling within this category as illegitimate. However, some nations, including the U.S., have supported an understanding of self-defense that could include prevention under certain conditions.
Why does it matter?
How a state legally accounts for its actions, both in the public record and in the context of international organizations such as the United Nations, affects the legitimacy that fellow nations afford to the state generally and to its action in particular. A state that consistently acts in ways deemed illegitimate may experience damage to its global relationships or censure under international law.
What standards does the international community rely on when determining legitimacy?
When determining the legitimacy of a pre-strike action, both historical practice and statutory interpretation can influence the analysis. Clashes of interpretation can result in controversy over what types of pre-strike attacks states should consider lawful.
One major source of variation in nations’ legal analyses stems from differing views on the interplay between Article 2 and Article 51 of the U.N. Charter.
Article 2(4) forbids states from engaging in the threat or use of force against each other. Yet Article 51 says that the charter does not prohibit 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 measures necessary to maintain international peace and security.”
As Georgetown professor Anthony Clark Arend explains, the restrictive school of interpretation believes that the language requires an attack to occur before one state can legitimately use force against another. But less restrictive arguments hold that a state need not wait until an armed attack has occurred to launch a legitimate pre-attack strike. This view leans on the weight of the “inherent right” of self-defense to argue that a state should be permitted to act to defend its citizens when it believes an attack is impending. Some taking the less restrictive approach also point to the French translation of the U.N. Charter, which uses the phrase “armed aggression,” as supporting a more flexible temporal approach to self-defense.
The U.N.’s 2004 High-Level Panel on Threats, Challenges and Change took a less restrictive view but qualified it, noting that:
according to long established international law, [a threatened State] can take military action as long as the threatened attack is imminent, no other means would deflect it and the action is proportionate. The problem arises where the threat in question is not imminent but still claimed to be real: for example the acquisition, with allegedly hostile intent, of nuclear weapons making capability.
Under the U.N. Charter, the Security Council has the sole ability to authorize the use of force against a state. If a state fails to receive this authorization but makes a pre-strike attack regardless, claims of self-defense will face much closer scrutiny.
When have states cited self-defense to justify a pre-attack strike?
Several brief descriptions of pre-attack strikes that relied on explicit or implied self-defense reasoning follow, each roughly falling into the subcategories described above. Arend provides a helpful overview of several of the below examples, as does Deeks. Their scholarship, along with public reports on the events, inform these descriptions.
In 1962, before either the Soviet Union or Cuba used force against it, the U.S. government instituted a “defensive quarantine” against Cuba. Some considered this to constitute a blockade under international law that is regarded as an act of aggression. Thus a blockade would violate restrictions on the use of force under Charter Article 2(4) or would require the U.S. to assert a legal argument claiming self-defense—a shaky proposition. By arguing that the defensive quarantine did not technically qualify as a blockade, the U.S. attempted to dodge the need to provide legal justification for the use of force.
Instead, in deliberations with the international community the U.S. focused its legal rationale on regional organizations’ power to authorize force rather than rely on legitimacy derived solely through self-defense. In Security Council debates over the issue, no clear consensus supporting or rejecting the doctrine of preemption emerged. Some indicated that while self-defense before an attack was legal, the U.S. had not met the strict Caroline standard.
The Six-Day War, one of the most commonly cited examples of a preemptive strike, began on June 5, 1967, when Israel launched a surprise attack against Egyptian forces. In the course of the short conflict, Israel more than tripled its territorial claims while repelling an assault it believed posed an imminent threat.
Several factors went into Israel's decision to strike, particularly Egypt’s expressed hostile position, its decision to expel U.N. forces from the Sinai and its closure of the Straits of Tiran. Ultimately, after significant political negotiation and the failure or rejection of several other courses of action, the Israeli government decided on a military strike to defeat the perceived existential threat posed by Egypt, along with its allies such as Syria and Iraq.
The Israeli position has consistently presented the 1967 war as defensive, legally justified by the actions and positions of its opponents. Many historians take a similar view. Yet other experts and many Arab states have called the conflict a war of Israeli aggression and deemed it unjustified given conditions on the ground.
The Israeli action drew mixed international reaction, and Israel largely avoided criticism within the U.N.
- Operation Opera (Osirak Bombing)
On June 7, 1981, Israel launched an airstrike against the Osirak nuclear reactor in Iraq, close to Baghdad. Although the facility was not yet operational, the Israeli government feared Osirak would become capable of producing material necessary for a nuclear bomb.
In a statement after the attack, the Israeli government said that its intelligence indicated the reactor would have become operational by July or September of that year. Given that Israel could and would not attack a “live” reactor site for fear of nuclear contamination, it claimed to have a small window for action:
We were therefore forced to defend ourselves against the construction of an atomic bomb in Iraq, which itself would not have hesitated to use it against Israel and its population centers. Therefore, the Israeli Government decided to act without further delay to insure the safety of our people.
The rationale behind the decision explicitly employed the future tense: At some point Iraq would have nuclear weapons capability that it would then likely use against Israel, judging by its past statements and the beliefs of Israeli intelligence. Yet Israel lacked clear indication that Iraq had the capability to carry out the attack, shifting the action closer to prevention than preemption.
The U.N. Security Council, including the U.S., unanimously condemned the attack, calling it a violation of the U.N. Charter and international norms.
- Operation Infinite Reach (Al Shifa Bombing)
In 1998, the U.S. conducted its first “unreservedly acknowledged” preemptive strike against a terrorist organization. In a plan codenamed Operation Infinite Reach, the Clinton administration launched a missile attack on a factory in Khartoum, Sudan, that it said produced the VX nerve agent for Osama bin Laden. The factory, however, produced pharmaceuticals for the Sudanese population. Many Arab nations condemned the attack as a violation of Sudanese sovereignty.
As with other claims to self-defense, this classification has come under significant scrutiny. Some argue that the strike is better understood as a post-attack response to the bombings of the U.S. embassies in Kenya and Tanzania that had happened shortly earlier that year. Reports in the years after the Sudan attack showed that the intelligence used in the decision contained significant gaps.
Although the George W. Bush administration legally justified its decision to send forces into Iraq in 2003 on the basis of Security Council resolutions, the administration relied in part on a claim of self-defense. The Bush administration argued that Saddam Hussein's regime armed with weapons of mass destruction presented a threat to both the region and the United States. In context of the Bush administration’s views and statements on pre-strike attacks in the National Security Strategy of 2002, this justification veered close to a doctrine of preventive self-defense: an allegedly guaranteed threat on a more ambiguous timeline that had to be stopped before it could achieve the capacity to strike. President Bush said in a speech Oct. 7, 2002:
Some ask how urgent this danger is to America and the world. The danger is already significant, and it only grows worse with time. If we know Saddam Hussein has dangerous weapons today—and we do—does it make any sense for the world to wait to confront him as he grows even stronger and develops even more dangerous weapons? … America must not ignore the threat gathering against us. Facing clear evidence of peril, we cannot wait for the final proof, the smoking gun that could come in the form of a mushroom cloud. …
The ideological framework underlying this policy proposal should not have come as a surprise. The National Security Strategy of 2002 explicitly suggested a more flexible understanding of what constitutes an “imminent” threat (which would legitimate certain military actions in self-defense). In it, the administration made similar arguments, noting that the government could use the likelihood of a future threat to justify immediate action.
- Operation Orchard (Al Kibar Bombing)
In 2007, Israel launched another airstrike, this time against a secret nuclear reactor named Al Kibar that had been constructed by the Syrian government in a remote part of that country. The attack continued the Begin Doctrine, an Israeli policy stemming from the 1981 Osirak strike, which said that Israel would not permit its adversaries in the Middle East to develop nuclear weapons.
The strike succeeded, covertly destroying the reactor. Intriguingly, parties kept virtually silent in the leadup to the strike and its aftermath. Details about the strike emerged only slowly. Deeks contrasts the lack of outcry over Israel's 2007 bombing with the swift international condemnation after the Osirak bombing, even though Al Kibar clearly did not meet the Caroline standards. She notes that WMD in the hands of states deemed unpredictable may affect international responses to strikes taken in asserted self-defense.
What can these events tell us?
The North Korean threat presents a host of challenging strategic questions regarding a pre-attack strike. This piece does not focus on the strategic logic or illogic of such a choice, which have been well addressed here, among other places. It considers instead a different question: What legal justification could the U.S. invoke should it choose to launch a pre-attack strike on North Korea?
First, we should consider which type of justification the decision would fall under. Assuming the U.S. has no immediate indication that North Korea is about to attack (eliminating the standard anticipatory self-defense requirement), the U.S. is likely to find itself somewhere between preemptive and preventive action. The North’s threatening statements and demonstrated technological development seem to indicate a real, rapidly approaching threat. Our knowledge of the weapons Pyongyang possesses and those the regime hopes to develop support the preemption classification. Still, preemption exposes the U.S. to possible legal objections and controversy.
The U.S. would probably argue that the North Koreans’ development of an ICBM and a soon-to-arrive nuclear warhead small enough to arm that missile present an existential threat to Americans' well-being and could destabilize global geopolitics. It could seek the authority of a Security Council resolution, in which case the legal question of an imminent threat would fall to the wayside—preventive force authorized by the U.N. Security Council is legal. But China and Russia have both shown willingness to support the North Korean regime in various ways, and their veto power over a Security Council resolution could prevent such a measure from ever coming to fruition.
In that case, the U.S. would likely assert that North Korea poses an imminent threat as per its understanding of Article 51 of the U.N. Charter and launch a preemptive strike. The examples above, and other instances not covered here, provide precedent.
But the approval of the international community for acts of preemptive self-defense—if it appears—stems from unique, contextual factors. The 2007 Al Kibar bombing faced little condemnation while the 1981 Osirak bombing sparked international outcry. Granted, the former benefited from more secrecy. But it was also a strike against an adversary that had progressed further along its path of obtaining destabilizing weapons and thus posed a more imminent threat. Perhaps in such a case international willingness to accept or ignore actions designed to resolve a major security threat increases. In the Osirak example, claims of self-defense appeared far more dubious as Iraq’s capabilities, and its intentions, were less clear. Although the threat included an alleged WMD component, it did not appear to pose imminent danger to international order, possibly leading to accusations of illegitimacy.
This key difference suggests a broader point: The threat of a rogue state with WMD casts a degree of unpredictability on how states, fearful but constrained, will react. While in some cases they may be more likely to support a pre-attack strike, in others they could worry about the target state’s response and the potential of an illegitimate and poorly timed pre-attack strike to spiral into broader regional or global chaos.
These strategic ramifications and the potential for long-term conflict appear especially concerning when decision makers may base their actions on non-public intelligence that, if one day revealed, could bolster or damage claims to legitimacy. This happened when intelligence—or the lack thereof—was released after the Al Shifa pharmaceutical plant bombing. More recently, the U.S. decision to enter Iraq in 2003, which was supported with questionable intelligence, continues to influence U.S. foreign policy (with, among other things, a Rand Corp. study noting that the experience in Iraq is likely to decrease U.S. willingness to launch preemptive strikes in the future). It is likely to continue to influence international perceptions of future U.S. claims of anticipatory legitimacy.
In short, the limited ground covered in this piece amounts to the following: The U.S. could make a substantial legal argument, based on international law and the precedent of some cases, for a pre-strike attack on North Korea. But the variability of historical examples and the behavior of Security Council members make it unclear what degree of legitimacy the international community would afford the United States’ fateful decision.