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How Should a Christian Approach War, Peace, and World Order?

As a college student interested in foreign policy and grand strategy, I applied for the AEI Values & Capitalism Summer Honors Program searching for ways to incorporate my Christian faith into my approach to international relations and armed conflict. While I left with still more questions than answers, I gained valuable insight into how Christians throughout history have approached these topics. Of the documents covered during my “Christian Faith and American Foreign Policy” class at AEI, which was taught by Dr. Will Inboden, I found St. Augustine’s City of God to provide the most insight.

In Book XIX, Augustine examines the ends of war, eventually concluding that the “ultimate purpose of war” is peace. Yet, because men are subject to competing and irreconcilable interests, they fight to ensure that a post-war peace is “the kind of peace they wish for” (866).

Reading Augustine’s argument presented me with another crucial question: why is war fought at all? Augustine’s answer, as mentioned above, is to decide which vision of post-war peace will triumph. Somewhat remarkably, his assessment resembles that made by Clausewitz in his landmark work On War. In famously labeling war “the continuation of politics by other means,” Clausewitz notes that war features a set of political objectives which it aims to fulfill (Book 1 Ch. 1).

Taken together, Augustine and Clausewitz argue that war must never be thought of as an end in itself. Instead, war should be viewed in terms of the specific policy goals that each side wishes to accomplish. Yet, as Augustine notes, not all of men’s visions of the future are equally desirable, nor are they equally just. Some men seek “to impose [their] own dominion on fellow men, in place of God’s rule,” Augustine explains. “Compared with the peace of the just,” he continues, “the peace of the unjust…is not worthy even of the name of peace” (869).

Given his remarks in City of God, Augustine is often considered the original just war theorist. However, according to his theory, war results when men, unwilling to compromise, cling to differing visions for post-war peace. If disagreements over the goodness or justice of post-war outcomes drives war, then what defines a just peace?

First, a just peace protects human dignity and freedom.

Despite increasing tensions within American society, the belief in a sense of shared inherent human dignity unites virtually all Christians with a variety of secular groups. However, making this idea a reality in foreign policy can be exceptionally challenging. Policymakers must grapple with how to reconcile their responsibility to serve their constituents with a broader obligation to promote human life, liberty, and happiness. This charge also mandates that decision-makers minimize the use of military force. A nation’s leaders have a variety of economic and diplomatic tools at their disposal. Before taking a human life, decision-makers should exhaust all other available means to accomplish their desired ends.

Second, a just peace preserves order.

Since 1945, America, along with other western democracies, has worked to create a series of institutions that bring order to an otherwise anarchical international system. Though this system (often referred to as the “liberal international order”) is imperfect in many ways, its implementation has allowed for peaceful dispute adjudication, promoted international cooperation, and condemned wanton aggression. For these reasons, America should not completely abandon the liberal international order, despite the prevalence of “free-riding” states that benefit from the system while contributing little. At a time when “revisionist regimes” seek to rework the world order for their benefit, America should strengthen and defend existing international institutions.

Third, a just peace is vigilant.

Following the collapse of the Soviet Union, America’s foreign policy decision-makers enthusiastically welcomed in the dawn of a “unipolar moment.” Most emblematic of the era’s rampant idealism was Francis Fukuyama’s pronouncement of “the end of history.” The victory of Western democratic capitalism over socialism and authoritarianism, Fukuyama argued, offered a final verdict on the age-old question of how humans should govern themselves.

Yet–perhaps unsurprisingly–American idealism quickly faded. The humanitarian crises in Rwanda and the Balkans in the 1990’s, the rise of global terrorism in the early 2000’s, and the return of widespread authoritarianism in the 2010’s demonstrated that a widespread peace will rarely go unchallenged. These examples demonstrate that, even amidst relative peace, justice must be actively pursued if it is to be maintained.

“The stubbornness of human selfishness makes the achievement of justice in human society no easy matter,” explains 20th century theologian and international relations theorist Reinhold Niebuhr. “Where there is sin and selfishness,” he adds, “there must also be a struggle for justice” (Christian Faith and the World Crisis, 149).

Overall, my most important takeaway from AEI was a perspective shift. Rather than solely contemplating what constitutes just war, I also began to reflect on what constitutes just peace. In 1 Timothy 2:1, Paul describes the role of government as the guarantor of “a peaceful and quiet life” for its citizens. By promoting international cooperation and discouraging conflict, the liberal order has fulfilled this task relatively well. Therefore, as America works to promote a just peace for those at home and abroad, it should work to reform and strengthen the institutions that have promoted human dignity and brought some order to the international system.