Justifying Going to War
Steven P. Lee
Jus ad bellum is the part of just war theory that concerns the justification for going to war, for starting a war or entering one begun by another state. Jus ad bellum consists of several criteria, necessary conditions, each of which must be satisfied for going to war to be justified. The main criterion is just cause—a state cannot go to war unless it has a reason for going to war that justifies its doing so. The standard view of much recent just-war theorizing is that self-defense (or collective defense) is the only just cause, a view which is embodied in the nonintervention principle, according to which a state, due to its sovereignty, is immune from military interference unless it has engaged in external aggression.
There are problems with the standard view. First, it is not clear why national defense is the only just cause. In support of the claim that it is, appeals are made to a domestic analogy, according to which states are like an individuals in domestic society. Given that for such individuals, the only justification for the use of force against others is self (or collective) defense, the same holds for states. But this appeal, I will argue, is not persuasive. Second, most just war theorists recognize some exceptions to the nonintervention principle; they regard some cases of nondefensive intervention as justified. Those alleged exceptions are usually cases of humanitarian intervention, a state’s use of military force to protect the citizens of another state from their own government. But such exceptions to the nonintervention principle seem ad hoc, lacking a well developed theoretical underpinning.
A better theoretical account is needed, one that recognizes the defense justification, but grounds that justification in a broader normative framework, a framework able to provide answers to questions about the justifiability of nondefensive forms of military force. In this paper, I begin an effort to provide such a theoretical account. I will focus on humanitarian intervention (HI) as the form on nondefensive intervention most widely recognized as a justified exception to the nonintervention principle. I will seek to provide some comments toward a general normative account of just cause that subsumes both defensive war and HI and that replaces the standard view, described above, which treats defensive war as the paradigm case and HI as, at best, a justified exception. I see this effort as complementary to some more recent writings on just war theory that also challenge what I am calling the standard view on the nature of just cause, such as work by David Rodin and Jeff McMahan.
The just war tradition is based on a political theory that draws a sharp distinction between domestic and international affairs. The standards of justification for the use of force are assumed to be different in the two realms, with just war theory representing the standards for the use of force internationally. Indeed, there are major differences between domestic and international society, and the standard view is that these differences require different normative accounts of the use of force, that they imply that the use of force domestically is morally discontinuous from its use internationally. But an alternative view is that there is a basic moral continuity between the use of force in the two realms, that there is a single account of the justification of the use of force, though one whose application to the domestic and international realms may yield different results, due to the differences between the two realms. This is the possibility I will pursue.
To assimilate in moral terms the international and the domestic use of force would be to adopt a cosmopolitan perspective. Cosmopolitanism holds that individuals, irrespective of the societies in which they live, are of equal moral value and are the chief, if not only, basic source of moral value. If social entities, such as states, have any moral value at all, it is derivative from, or merely instrumental in regard to, the basic value of individuals. At the domestic level, the justification for the use of force by governments is the protection of those individual rights which collectively represent recognition of the moral value of the individual.
Behind the idea that the international realm is morally different from the domestic realm is the idea of state sovereignty at the international level. Sovereignty, as traditionally understood, stands in the way of a common moral theory of the use of force because it gives moral value to states that is at least partly independent of the moral value of the individuals composing them. This inherent moral value in states is represented by their sovereignty. A single justificatory theory of the use of force covering both the domestic and international realms would have to abandon the assumption that sovereignty has any independent, noninstrumental moral value. This is what the cosmopolitan does; she maintains that the protection of individual rights is the sole ultimate justification for the use of force, not just domestically, but also internationally. Just war theory would have to be recast in terms of individual rights.
There is one major objection to the claim that there could be a unitary normative theory of the use of force. The primary difference between the two realms on which the claims of moral discontinuity hang is the lack of an overarching governing authority at the international level such as that which holds at the domestic level. The use of force must be treated differently at the international level because, in the absence of a global government, the use of force between states cannot be legally sanctioned. Legal sanction is necessary for the justified use of force. But this objection assumes that the justification for the use of force must be a legal justification. On the contrary, a legal system can provide an adequate justification for the use of force only if it is a justified legal system, that is, only if it is morally acceptable. Justification for the use of force must ultimately be a moral justification, and it may not be that such a justification must involve the moral intermediary of a legal system.
This point is recognized in the distinction drawn between moral and institutional cosmopolitanism. Moral cosmopolitanism is the idea, mentioned above, that individuals are of ultimate and equal moral value. In contrast, institutional cosmopolitanism is the idea that there ought to be strong global governing institutions. The full realization of moral cosmopolitanism may or may not require such institutions, but moral cosmopolitanism can justify actions, such as the use of force, independent of the existence of such institutions. As Charles Beitz puts it,
It is important to distinguish moral structures from political ones, and to recognize that global moral principles might be implemented otherwise than by global institutions conceived on analogy of the state.
Human rights ought to be respected, which implies that no state should violate them. There is an obligation not only not to violate rights, but also to seek to protect individuals from having their rights violated by others. Because rights are universal, this need to use force to protect individuals from rights violations may apply internationally, as well as domestically, whether or not appropriate legal structures are in place.
Many individuals live under governments that either systematically violate their rights (as in an oppressive state) or fail to stop other individuals from violating them (as in an inept or failed state). Of course, it is the duty of each government to promote respect for the human rights of its citizens, but when it fails to do so, as is unfortunately often the case, other governments may be justified in using force to remedy the situation. Almost everyone believes that HI is justified in some cases, specifically, cases of extreme human rights abuses, such as genocide. The problem is to find an adequate normative account of HI that will support these beliefs, that will show how HI is justified in such cases to.
As discussed earlier, the usual approach to this is to begin with the ideas and principles of just war theory and state sovereignty, from which HI is treated as an exception to the nonintervention principle. As one recent theorist puts it:
Humanitarian intervention is generally treated as an exception to the nonintervention principle, which requires us to respect the integrity of a foreign country and not to interfere in matters of domestic jurisdiction.
Thus the question is: How is it that HI can be justified as an exception to the nonintervention principle? Most often, the justification is simply asserted.
Grievous violations of human rights, including ethnic cleansing, massacre, and other acts that “shock the moral conscience of mankind,” are just too serious to be regarded merely as a matter of domestic jurisdiction.
One has sympathy with this claim, but still, an argument is needed. Perhaps a different approach would work better, an approach that did not begin with the ideas of sovereignty and just war theory, as understood by the standard view.
The alternative approach I will develop considers matters from the other end, so to speak. The standard view, as discussed, assumes that there is a moral discontinuity between the domestic and international uses of force, a discontinuity represented by the ideas of sovereignty and the nonintervention principle. An alternative approach is to understand the justification of the international use of force to support respect for human rights as continuous with the justification of the domestic use of force, in the sense that the same basic set of principles applies. Justified use of force to protect human rights abroad would be of a more limited scope than in the domestic case, a difference flowing from various differences between the two cases. But the limitations that apply on the use of force are of the same kind as those that apply, though to a different extent, at the domestic level. There would not be a fundamental difference, as represented by an appeal to sovereignty or the nonintervention principle, that would create a fundamental discontinuity between the cases.
My alternative approach is to consider the morally justifiability of HI by generalizing from the moral justification of domestic use of force to support respect for human rights, thus treating the two cases as morally continuous, not sharply divided by principles of nonintervention or sovereignty. The universality of human rights implies that borders between states should not mark a sharp moral discontinuity. At the same time, I recognize that there is an apparent discontinuity between the domestic and interstate cases, which the principles of sovereignty and the nonintervention attempt to capture, and I will try to address this appearance.
Consider now the domestic case. Obviously, the most important domestic limit on the state use of force is that it not be used for oppression. But, even when force is used domestically for its proper purpose, to support respect for human rights (as in standard criminal law), the scope of its justified use is limited. It is clear that state force should not be used so as to seek to avoid all human rights violations. The general idea behind these limitations is that some use of force to support respect for human rights would be counterproductive. These counterproductivity limitations fall into two general categories: (1) efficiency limitations and (2) rights-balancing limitations.
(1) Efficiency limitations concern both:
(1a) the ability of government power to achieve adequate protection of the rights in question and
(1b) the cost in scarce resources of its attempt to do so.
(2) Rights-balancing limitations involve the costs in rights violations that tend to accompany efforts to support respect for rights. These limitations result from the need to balance the rights violations that may result from the use of force against the respect for rights that the use of force achieves. Rights violations may follow from use of force by the state because:
(2a) when government uses its power to seek to protect rights, it may inevitably violate other rights and
(2b) the tendency of government to become oppressive, to use its power to seek to violate rights rather than protect them, can be exacerbated when it is given greater power, as it is when it is charged with using force to protect rights.
Efficiency limitations are a consequentialist matter. In contrast, rights-balancing limitations are a deontological matter.
To see how these limitations work in the domestic case, consider rights violations involving lying. While each person has, in general, a right not to be lied to by others, no one thinks that state power should be used to suppress lying (apart from special cases, such as contracts, court testimony, or lies by government). The reason may be explained in terms of either kind of counterproductivity. It would be inefficient to use state power to promote respect for a right not to be lied to because:
(1a) the government is unlikely to be very successful at achieving this goal and
(1b) the extent of governmental resources involved in a serious effort to achieve this goal would be disproportionate to the value of the rights-protection that would be achieved.
At the same time, there are also rights-balancing limitations to such use of state power because:
(2a) the right against being lied to could be protected by state power only at the expense of other rights, specifically, privacy rights, which would inevitably be violated by the intrusiveness necessary to protect this right and
(2b) the extensive power assumed by government in any effort to suppress lying could easily cause the government to end up using that increased power oppressively.
It seems that either efficiency limitations or rights-balancing limitations would be sufficient, in this case, to deny government the power to seek to suppress lying.
The best way to show that there is a moral continuity between the domestic and international cases of the use of force to support the protection of rights is to cite domestic examples where the state’s use of such force is morally limited by respect for what goes on within social groups. The reason is that HI is a matter of interference in the affairs of a large social group, specifically another state. So, let us consider the way that the domestic use of government force is morally limited domestically by the fact that the rights violations it seeks to avoid occur within social groups. The activities of social groups in domestic civil society often involve the infringement of the individual rights of some of their members, and the state is often justified in using force to secure respect for those rights—but not always.
Consider the limitations on legal coercion in family law. Rights violations often go on within families, and the state is sometimes justified in interfering to avoid those violations. This is part of the import of the slogan, “the personal is the political.” Systematic violations of human rights within families, such as the mistreatment of women, should be subject to restriction by the state’s use of force. But there are limitations on the extent to which such coercive interference is justified, though these limits are subject to debate. In traditional family law, there is the doctrine of “oneness” of the family that, for example, restricts the applicability of tort law within the family. This doctrine is weaker now than it has been in the past, but it remains to some extent a barrier to state coercion.
The same is the
case in regard to children as family members. Parents have considerable, though
not complete, discretion in how they treat their children and the allowable
discretion encompasses parental behavior that would be considered a violation
of the individual rights of the children. In fact, we could define “child
abuse,” understood as justifying state interference, as the point at which the
violations of the rights of children become sufficient to justify the use of
force to suppress them. A number of states in the
The fact that there are limitations on state coercion to protect individual rights when the individuals are part of social groups, such as families, and that we generally regard such limitations as justified, indicates that there is something about the activities of an organized social group such as a family (as opposed, for example, to a random group of individuals) that implies those limits. What this something is can be explained in terms of the idea of counterproductivity limitations. In terms of efficiency limitations, the interpersonal relations within the social group would make the use of force to avoid the rights violations less likely to succeed and make the resource cost of attempting to do so greater (as when, for example, battered spouses refuse to testify against their batterers). There is another element sometimes present that impedes efficiency, namely, the tendency of victim and victimizer within a social group to join forces in opposition to the state’s attempt to avoid the rights violations the victim is suffering. Outside of social groups, victims of rights violations will almost always cooperate with the state’s efforts to prosecute the victimizer, but within social groups, often not. A vivid illustration of this is that spouses sometimes team up to resist the enforcement efforts of police called to the scene of a domestic dispute (often by the victim of the rights violations). The fact that these legal limitations can be justified in terms of efficiency limitations suggests that there is no need to postulate group rights to explain them.
In the domestic case, there is an initial presumption that the use of force to achieve respect for individual rights is justified, and one then recognizes qualifications on that presumption, as in the case of social groups, by citing bases for restricting the use of force in terms of efficiency or rights-balancing limitations. In contrast, the standard view of HI begins with the presumption that cross-border coercion to protect individual human rights is not justified (as represented by the ideas of sovereignty and the nonintervention principle), and then a case may be made for exceptions to the presumption, for example, in cases involving genocidal-level violations. My suggestion is from a theoretical perspective, one should look at international cases in the same way one looks at domestic cases: beginning with a presumption in favor of HI, which is then qualified in terms of efficiency or rights-balancing limitations. The limitations on HI are stronger than the limitations in the domestic case because the nature of the social groups in question (that is, states) implies the stronger limitations.
Nations are much larger and more complex social groups than those found within states. They have a number of features which may create efficiency or rights-balancing limitations countering the presumption in favor of the use of force by outsiders to protect individuals from rights violations. But I want to focus on one feature in particular, namely, the expectation that one state’s use of force against another, whatever the reason, would result in extensive forceful resistance on the part of citizens of the second state. The justifiability of such outside military interference is unlikely to make much difference in the expectation of forceful resistance. In terms of perceptions, one state’s HI is another state’s military occupation. Forceful resistance to an HI would be analogous to the domestic cases where family members band together to resist the forceful efforts by the police to protect the rights of some members against others.
There are two main reasons that extensive resistance is to be expected in the international case, whatever the reason for the military interference to which it is a response. First, states are organized to be able to mount forceful resistance to outside military interference—on many views this is the primary raison d’etre for the state. This is not in general the case with social groups within states, in part because states generally have a practical internal monopoly on the use of force. For example, the resistance that might be offered by a married couple collectively to an attempt by police to suppress domestic abuse would generally be spontaneous, sporadic, and not very effective. Second, the citizens of a state, at least a large portion of them, are in general highly motivated to support and participate in forceful resistance by their military to foreign military interference, even when that interference is justified, as is sometimes in the case with HI. This is due to factors such as nationalism, the foreign government’s having ideologically mobilized its citizens for that purpose, and the benefit that some of the citizens receive from the rights violations perpetrated against others.
it is an interesting question whether forceful resistance to a justified case
of HI is itself justified, from the point of view of efficiency limitations,
this question is not central. The question itself is the flip side of the
question whether the interference is a justified case of HI. Presumably, if the
HI is justified, resistance would not be (however much it is to be expected),
while if the HI is not justified, resistance would be. But the role of expected
resistance in considering the appropriate limitations on HI, from the
perspective of efficiency limitations, is a de
facto rather than a de jure
matter, so to speak. Expected resistance creates an efficiency limitation to
military interference, whether or not the interference or the resistance to it
is justified. Expected resistance means great loss of life and may make the
protection of the human rights in question difficult or impossible to achieve,
all factors central to efficiency limitations.
(The current war in
Michael Walzer argues that resistance to outside military interference is almost always justified (indeed, perhaps even obligatory) because such interference is ipso facto a violation of the rights of that society to determine its own political fate. Thus, in my terminology, he argues that rights-balancing limitations generally preclude a nondefensive use of military force, such as HI, and he does this by postulating a kind of group right, the right of a political community to determine its own political arrangements. (In this context, he argues in favor of HI in extremis as an exception by claiming that when genocidal rights violations are going on in a state, the political community within that state has effectively has broken down. Without the community, there is no group right the violation of which would morally stand in the way of HI.) The appeal to such a group right echoes the doctrine of “oneness” of traditional family law. But the argument can advance without such an appeal to a group right. Instead of appealing to rights-balancing limitations on military interference, which, in this case at least, involves a reference to group rights, one can appeal to efficiency limitations. One need not postulate group rights in an account of HI; individual rights, along with efficiency counterproductivity, can do the job.
Sovereignty is a legal concept, and, as such, it is not sufficient to show that HI is not morally justified. The question is whether HI is morally justified, not whether it is legally justified. Arguments about HI make a moral, not a legal, appeal. The moral claim is that respect for individual human rights ought to be promoted and that force may sometimes be used for that purpose, and, because those rights are universal, this may sometimes involve military force across borders. As such, the above argument is not falsified by the division of the globe into legally sovereign states. Though a state has legal authority to use force against its own citizens, while lacking legal authority to use force against others, the questions if and when the use of force abroad is morally justified is an independent matter. Legal sovereignty may be (and almost certainly is) generally of instrumental moral value, but, as such, respect for it would be at best a defeasible moral rule of thumb (justifiably set aside in the case of civil disobedience, for example). The fact that sovereignty is widely recognized and often fiercely defended affects the moral argument, but only indirectly, by contributing to the circumstances to which our moral practice must respond in terms of the two kinds of limitations outlined earlier (especially efficiency limitations). I have emphasized the expectation of resistance as a factor leading to an efficiency limitation on the justifiability of the use of force to promote respect for individual human rights, a factor that applies at both the domestic and international levels. But the fact that sovereignty is widely regarded as legitimate means that it plays a stronger role in limiting the international use of force. In any case, sovereignty cannot show HI to be in general unjustifiable. As a principle of international law, sovereignty is, like any other principle of law, domestic or international, subject to moral criticism. To the extent that HI is disallowed by the legal principle of sovereignty, a state’s practice of HI, when it is morally justified, is like a citizen’s justified practice of civil disobedience on the domestic level.
In the case of governmental use of force, the moral continuity between its domestic and its international cases is that both may be justified in terms of the protection of individual rights within social groups, whether or not the groups are under the legal authority of that government. The domestic use of force must deal with social groups in civil society (families, religions, etc.), and the international use of such force must deal with larger and more powerful social groups, namely, nations. The fact that moral limitations on the use of force to protect human rights are more stringent in the international case than in the domestic case follows from the application of the same kinds of limitations in the two different contexts. This yields a much higher moral barrier to the use of force to protect human rights abroad, but the height of the barrier does not imply that different moral principles (such as the nonintervention principle) are at work in that case.
If there were a true global government, the legal justification for the use of military force would be the same as the legal justification of domestic police force; in fact military force would be police force. Whether a true global government will ever emerge is, of course, unknown, and it is not clear that it would be a good thing morally if it did. But until, if ever, such a government comes to be, we need a way of protecting human rights within states that do not respect them. There are mechanisms for this short of military interference that should be tried first; HI, as any war, should always be a last resort. But cases like the Rwandan genocide show that it will sometimes be necessary to use force.
This account affirms the centrality of defense as a just cause, on the grounds that defense seeks to avoid the massive violations of rights occasioned by aggression, but it also shows why and how humanitarian intervention is justified, and it establishes a theoretical basis for addressing questions about the justifiability of other forms of nondefensive intervention, such as preventive intervention. It provides the basis for a more cosmopolitan, less statist conception of just cause, and an alternative reconstruction of just war theory.
 Another form of nondefensive intervention is preventive intervention, the use of force to prevent a state from engaging in expected or feared future aggression. The Iraq War is an example of preventive intervention. Preventive intervention is nondefensive in the strict sense because it seeks to protect not against an actual or imminent aggression, but a potential, future one. The theory I seek to develop should also be able to tell us about the justifiability of preventive interventions.
 See, for example, David Rodin, War and Self-Defense (Oxford University Press, 2002) and Jeff McMahan, “Just Cause for War,” Ethics and International Affairs 19, no. 1 (2005), pp. 1-21.
 In this paper, “the use of force” refers to both the application of force and the threat of its application.
 A number of people have purposed such an idea, for example, David Luban in “Just War and Human Rights,” Philosophy & Public Affairs 9 (Winter 1980), pp. 160-181.
 The United Nations and its Security Council partially fulfills the role of an international organization authorized to permit the international use of force. But it is too weak and undeveloped to be counted as a true global government. I will discuss the role of the UN in our thinking on this topic later.
 Otherwise, civil disobedience at the domestic level could not be justified.
 This distinction is recognized by Charles Beitz, Political Theory and International Relations, 2nd ed. (Princeton, NJ: Princeton University Press, 1999), pp. 182-83, for example.
 Beitz, Political Theory, p. 183.
 See, Henry Shue, Basic
Rights: Subsistence, Affluence, and
 Carla Bagnoli, “Humanitarian Intervention as a
Perfect Duty: a Kantian Argument,” in Terry Nardin and Melissa Williams (eds.),
Humanitarian Intervention (
 Bagnoli, “Humanitarian Intervention,” p. 118.
 Some authors criticize contemporary accounts of just war theory, such as that of Michael Walzer in Just and Unjust Wars (New York: Basic Books, 1977), for their excessive and legalistic reliance on the idea of state sovereignty. For these authors, more traditional accounts of just war theory place more emphasis on the pursuit of human good and less on respect for sovereignty. As a result, approaching the justification of HI through the traditional accounts of just war theory may not be susceptible to the criticism in this paragraph. See, for example, Joseph Boyle, “Traditional Just War Theory and Humanitarian Intervention” and Anthony Coates, “Humanitarian Intervention: A Conflict of Traditions,” both in Nardin and Williams (eds.), Humanitarian Intervention.
 These two sorts of efficiency limitations are related because the ability of government power to succeed in promoting respect for a certain human right is in part a function of the amount of resources applied to that purpose.
 Though rights balancing limitations involve what is sometimes referred to as a” utilitarianism of rights.”
 For example, in the name of “family values” some would deny the state access to the inner workings of the family in order to protect the male privilege that is the flip side of the rights violations of the women involved. Others would endorse an increase in state power to interfere in families to root out that old form of privilege.
 Harry Krause, Family Law in a Nutshell, 2nd ed. (St. Paul, MN: West Publishing Co., 1986), p. 116.
 Krause, Family Law, p. 196.
 Krause, Family Law, p. 131.
 Some might see such limits as an indication that there are group rights that the state use of force would violate, rights respect for which must be balanced against the rights violations going on within the group. This would be a rights-balancing limitation. But the availability of an appeal to efficiency limitations to justify the enforcement limits, as discussed in this paragraph, may allow us to avoid an appeal to rights-balancing limitations, and so save us from the need to rely on the controversial idea of group rights.
 Daniel Kofman refers to the belief that an HI is
unlikely to succeed it avoiding the rights violations as “feasibility
skepticism;” see his “Moral Arguments: Sovereignty, Feasibility, Agency, and
Consequences,” in Thomas Cushman (ed.), A
Matter of Principle: Humanitarian Arguments for the War in Iraq (
 It may be a factor to be considered under rights-balancing limitations that many of the deaths resulting from an HI would likely be those of the intervener. This is thinking of HI as analogous to Good Samaritan actions in the domestic case. When the price is too steep for me as an intervener, I am not required to act to protect another from a human rights violation. But this analogy assumes that HI is a matter of obligation, not mere permission.
 Walzer, Just and Unjust Wars, pp. 53-54.
 Walzer, Just and Unjust Wars, p. 101.
 This argument strikes me as ad hoc. Was the political community broken in Nazi Germany during the Holocaust? Empirically, it seems not. One could stipulate that the community had broken down normatively, but then the argument becomes question-begging.
 What about the issue of partiality, that is, in this context, the idea that a government has responsibilities toward its own citizens that it does not have toward foreigners? I cannot explore this question in any depth, but even if we assume that partiality carries independent moral weight (as opposed to its simply being a stand in for other relevant factors such as, for example, epistemological concerns about our ability to know about rights violations), still there are ways to incorporate a concern with partiality without abandoning the justifiability of HI. For example, partiality could be factored into the moral calculus, perhaps showing up as a rights-balancing limitation on justified HI, or we might argue that partiality entails that, whereas domestic coercion to protect rights is obligatory, foreign coercion for that purpose is merely a matter of permissibility. (One omission in this paper is that it has not addressed the distinction between the merely permissible and the obligatory.)
 All along, I have been writing as if the agent of HI
is an individual state, but this need not need be the case. An HI can be
authorized and/or undertaken by a regional association (as with NATO in Kosovo)
or the United Nations (as with the intervention in
 The role moral criticism in leading to changes in positive law may apply more strongly to international law than to domestic law. The reason is that one mechanism of change for international law, in the absence of a global legislature, is through evolving practices. States can seek to change the law by deliberately violating it, hoping to thereby establish a new norm.
 Military force, even when use for HI, is not currently police force because it is not charged with doing much of what police force is typically charged with doing. Military force is charged to prevent on-going human rights violations, as is police force, but it is not charged with other standard police functions, such as preventing human rights violations in advance or apprehending human rights violators for punishment. But this latter function may be one about to be assumed by foreign military forces in the case, for example, of the apprehension of suspects on warrants issued by the International Criminal Court.