What’s
Wrong With Pre-emptive War?
Kaufman
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
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”[1]:
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.[2] 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.[3] For Christine Gray, ‘anticipatory’ is but
another name for ‘preemptive.’[4] 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.[5] 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.”[6] 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.”[7] 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
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 (
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
Furthermore,
both White House Press Secretaries (Fleischer, McClellan) at different times
indeed claimed that
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.
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.”[9] 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
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
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.
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.
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
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
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.
NOTES
[1]
Anthony Arend, “International Law and the Preemptive Use of Military Force,”
The
[2]
“The Myth of Preemptive Self-Defense”
[3]
War, Aggression and Self-Defence
[4]
International Law and the Use of Force, p. 111 ff.
[5]
see e.g. Walzer p. 74-75; David Rodin, War
and Self-Defense, p. 113.
[6]
Uniacke, Justifiable Homicide, p. 165.
[7]
Defending Imminence p. 252. See also
Dinstein p.183-4, describing the 3 conditions of self-defense as necessity,
proportionality, and immediacy.
[8]
See, e.g., G.
[9]
Ramsey, The Just
War p. 61-69
[10]
Maggie Lawson, “The Fatal Legend of Preemptive War,” National Catholic
Reporter,