Just War

Just War Colloquium

Acton-Institute-Logo-GIF-150x150The Wheaton Center for Faith, Politics and Economics, in partnership with Acton Institute, hosted a Just War Colloquium this past winter. The following are articles based on papers presented at the two sessions of the colloquium.The first article discusses just war theory in reflection on terrorism in light of the 20-year anniversary of 9/11 and the other article looks at just war theory and cyberwar.


Just War

Just War: 20 Years since 9/11

By Eric Patterson, Ph.D.

2021 marks the 20th anniversary of the 9/11 attacks. The violence perpetrated by non-state actors, and the response of governments, reminds us of two related issues. First, who gets to decide to go to war? Second, who may legitimately fight in a war? I will call these Authority Legitimacy and Combatant Legitimacy.1 This essay discusses how the global war on terrorism raised a number of perennial issues about the legitimacy of government, supranational, and non-state actors, questions that the just war tradition, and its child, the law of armed conflict, provides thoughtful answers to.

The just war tradition is a Western philosophical school of thought with roots in the Greco-Roman world (e.g.,Cicero) and early Christianity (e.g., Romans 13, Augustine, and Ambrose). The classical just war framework provides the foundation for individual behavior, customary international law, and the formal laws of  armed conflict, in addition to ethical reflection on issues of war and peace.2 It is the foundation from which numerous Western political principles derive (e.g., sovereignty, political legitimacy, and just cause in war) and all of these are firmly rooted today both in international conventions and foreign policy practice. Just war thinking begins with three deontological criteria for the just decision (jus ad bellum) to use military force: legitimate authority acting on a just cause with right intent. Practical, or better, prudential,3 secondary jus ad bellum considerations include: likelihood of success, proportionality of ends, and last resort. Just war thinking also has criteria regarding how war is conducted (jus in bello): using means and tactics proportionate (proportionality) to battlefield objectives and which limit harm to civilians, other non-combatants, and property (discrimination). At war’s end, a durable peace should be founded on order, justice, and, efforts should be made to ultimate conciliation.

The just war framework presupposes a number of Christian doctrines, such as neighbor-love, stewardship, vocation, and justice.4 It also relies on a critical distinction between force and violence. Forceis lawful, restrained, and motivated toward the end of peace. Violence, in contrast, is unlawful, unrestrained, often perpetrated by those without legitimate authority, and motivated by something other than love, such as vengeance, greed, or lust. The Bible and Christian tradition teach that legitimate political authorities have a moral duty to vigilantly employ restrained force to counter lawlessness in domestic and international society. The key, therefore, lies in authority, motivation, and how force is employed. We can tell the difference between firm but loving parental discipline: it is quite different from anger-induced, unrestrained child-beating. So, too, we can tell the difference between law enforcement killing a murderous kidnapper to save a child as contrasted with unlawful police brutality. In short, violence is different than force: it is illegitimate, unrestrained, beyond the law, motivated by an anger verging on hatred, and dehumanizing. The same holds true with the application of military force in which there is a difference between lawful, restrained, morally guided fighting on the battlefield and immoral, unrestrained violence.


The hallmark of legitimate authority is not regime type, because all polities throughout history – whether democratic or not – are accountable for the morality of using force, whether at home or abroad. Just war thinking, then, is rooted in a political ethic of responsibility. When considering whether or not to go to war, policy makers should begin from the premise that the state has certain ethical and practical responsibilities, rooted in the social compact that leaders are responsible for safeguarding the lives, livelihoods, and way of life.5 Since the end of the Cold War, most conflicts are either illegitimate regimes harming their own people and destabilizing their neighborhood or non-state actors perpetrating terrorism against the citizens of legitimate governments. In either case, the authority for response comes not from an artificial conception of the equality of dueling belligerents butfrom the legitimate right of self-defense, which manifests itself not just at home but in protecting one’s neighborhood and the global commons. Governments are the authorities responsible to protect the lives and futures of their citizens and allies from the depredations of rogue states and terrorists. I call this responsibility Authority Legitimacy, which is rooted in the first jus ad bellum principle of “legitimate political authority.” But in the past 25 years the actors employing force are more complex than often realized: NATO (both in Kosovo and in Afghanistan), the U.S., the “coalition of the willing” in Iraq, and the United Nations (UN).

In contrast, 9/11 emphasized what was already a growing trend: highly armed groups of people murdering others with tremendous levels of firepower, whether in the form of Latin American drug cartels, Somali pirates, or terrorists (al Qaeda, ISIS). These groups are illegitimate, both morally and legally, for deciding on their own – outside government structures – to employ mass violence.The second perennial issue has to do with who is authorized to fight, or Combatant Legitimacy. This flows, in part, from the authority delegated by legitimate political authorities, thus members of law enforcement and national militaries are legitimate warriors. In contrast, the U.S. and its allies have had to deal with an unusual cast of “unlawful belligerents:” pirates, terrorists, criminals, mercenaries, and the like.

Despite the fact that the U.S. and its allies seem to be pivoting away from Middle East terrorism and refocusing grand strategy on great power competition (i.e. China and Russia), nonetheless, these issues will remain salient. Russia utilized soldiers in unmarked uniforms (“little green men”) in its recent invasion of Ukraine’s Crimea. China has an unofficial army of civilian cyberwarriors that the West is barely thwarting. Traditional terrorism and criminality continues. The U.S. and its allies continue to rely heavily on logistical support provided by private defense firms. Thus, the issues of authority, both in theory and practice, remain relevant in the fluid environment of global politics.

eric pattersonEric Patterson is the Executive Vice President of the Religious Freedom Institute and Scholar at Large, Regent University



1 To the colloquium readers: should I instead call it “Belligerent Legitimacy?”
2 The Greek concept of “morality” is usually translated as “character” (ethos) and the Roman term for customary behavior (morals) is moralis, so both words are used somewhat interchangeably in this article.
3 James Turner Johnson originated this wise description of the secondary jus ad bellum criteria and consistently uses it across numerous books and articles. In a famous First Things article he compared “several recently invented prudential criteria” to the original deontological trio of legitimate authority, just cause, and right intention (see his “Just War: As it Was, and Is” in First Things (January 2005). He says that the role of the prudential criteria, however important, is “secondary” in elucidating jus ad bellum in The War to Oust Saddam Hussein: Just War and the New Face of Conflict (Lanham, MD: Rowman & Littlefield, 2005).
4 See Eric Patterson and J. Daryl Charles, eds., Just War and Christian Tradition: Denominational Perspectives on War and Peace (forthcoming, 2021).
5 For an extended version of this argument, see Eric Patterson, Just War Thinking (Lanham, MD: Lexington Books, 2007), chap. 3.