Just War Theory

Is war ever justified? What grounds the ethical criteria to enter and conduct war? And how does this fit with Christianity’s individual conduct codes and the idea of pacifism?

With Thanksgiving and Halloween behind us, the country’s attention turns to Remembrance Day. As we observe it, we ponder the philosophy of war: is it ever justified?

Remembrance Day

Remembrance Day began as Armistice Day – a celebration of the end of World War I, which at that time was known simply as “the Great War” or “the war to end all wars.” World War I saw the battle of Vimy Ridge, Canada’s most celebrated military victory, memorialized by brigadier general Alexander Ross’s sentiment of witnessing in it “the birth of a nation.”. According to Veteran Affairs Canada, 2.3 million Canadians have served throughout our nation’s history, with more than 118,000 losing their lives in service.

The poppy is perhaps the best known symbol of remembrance. It was instituted in 1921, on madame Anna Guerin’s suggestion to sell them to raise money for veterans. Yes – the venerable symbol on our lapels turns a century this year. Madame Guerin was inspired by another Remembrance Day staple, the poem by Canadian physician and lieutenant colonel John McCrae, In Flanders Fields.

Just War Theory

Canadian Christians typically observe Remembrance Day, and in our ever-changing social environment it’s appropriate to take a few minutes to understand how to think and articulate a clear viewpoint on war. The philosophy of concern here is the just war theory, a well-cemented doctrine with significant Christian origins and contributions, but upheld by thinkers of varied beliefs and worldviews.

The just war theory is generally split into considerations for entering war, or jus ad bellum, and considerations for waging war justly, or jus in bello. In this theory, to justly enter a war a country needs to think through the following questions:

  • Is the reason to enter war morally valid? For example, is it about defending a nation, or more about an unjustified expansion of its borders, or looting another nation?
  • Is the war declaration being issued by a competent authority – the acknowledged rulers of the nation, as opposed to a band or other subversive element?
  • Is the nation going to war with the right intention? Is this war fought to protect justice; to defend what is right?
  • Is this war truly the last resort? Has all due diligence been exhausted to prevent this final and consequential step?
  • Is there a reasonable probability of success? Are we going into a senseless carnage that may not achieve just outcomes, or is there a sensible path to achieve justice at the lowest possible cost?
  • And finally: do projected results have proportionality? Does any expected goodness significantly outweigh the inevitable harm and loss of conducting the war?

These criteria have been refined through centuries of contributions by notable philosophers – in the case of Christianity, going all the way back to St Augustine.

But it’s not enough to have justified reasons to enter war. The war effort itself must follow just criteria. These include a proportionality in the use of force – the use of just as much force as absolutely required, and not more. They also include a meaningful and effective discrimination between combatants and non-combatants, unequivocally a very delicate issue when looking at any war. And good faith and the avoidance of evil means must remain constant throughout the effort. Prisoners of war should be treated justly, and at no point must armies take joy in killing and destroying just for the sake of evil.

Addressing Objections to Just War Theory

Not all Christians agree with just war theory. Aren’t we the people of “the gospel of peace,” of “turning the other cheek”? Non-believers frequently object to this theory too. Pacifists believe that war is never justified – that there cannot ever be a reason or set of reasons that warrants such an atrocious outcome. In this viewpoint, war is often perceived as a failure of reason and progress.

To address Christian reservations, I’ll echo theologian Wayne Grudem to explain that individual codes of conduct in the Bible shouldn’t be applied to the way national affairs are conducted. Romans 13 and 1 Peter 2:14 establish the basic duty of government, which is to preserve social order, by coercing evil if needed. This begins internally, but extends to dealings with other nations if necessary.

However, stepping back, there is a bigger picture that exposes the root of these debates, whether you are a believer or not. Implicit in the tenets of just war theory is a presupposition: that war is inextricably woven into our reality. A postmodern culture will be tempted to ignore this. An idolatry of reason or technology can lead to the myth that social and political progress are also cumulative and inevitable, and therefore, to the possibility of leaving war behind for good.

To be sure, technology does play a role in war – a cruelly ironic one: it makes conflict less gory for front-line soldiers, but far more destructive in the aggregate. The way Greek and Roman soldiers fought in their time is nothing like the way British and American soldiers fought on Canadian soil in the War of 1812. That, in turn, looks nothing like the way the two World Wars of the 20th century were fought. And this changes again radically when you consider more recent conflicts. Modern war is less personal, less hand to hand, but ever more costly and destructive.

Technological advances in weapons development brought about mutually assured destruction, which gave us the Cold War. And now we must contend with cyber-war too. But all of this is in addition to – not in replacement of – real-life war. If anything, these advances have accelerated and exacerbated arms races in our time. Ultimately, physical war is at times inevitable.

The Bible certainly doesn’t contemplate a future without war. In fact, Jesus warned his followers that they’d hear of wars and rumors of war before the end came (Mt 24:6). The way biblical prophecy works, this isn’t a one-off situation that will happen right at the end of the times, but something that will repeat again and again over centuries.

In human and global terms, war is a sadly common reality, especially when we look beyond the developed world. Even when countries are not at war, so many of our daily interactions, and even our social efforts, are tinged by the material reality of war, which enters our vocabulary on issues like drug law enforcement, or how to control and eradicate illiteracy or poverty or pandemics.

I must clarify and emphasize what I am not saying. I am not saying war is a reality to be engaged lightly and happily. I am not saying that any arbitrary war can be correctly construed as a just war. Christians in particular need to be very careful about the temptation of civil religion. Unfortunately, the foundational influence of our faith in Western democracies has often been co-opted to conflate political and military calculations with God’s will, and His blessing with the apparent success of purely human campaigns rooted in chauvinism and not at all justifiable.

Lest We Forget

Ultimately, while we could debate for hours whether a particular war was just or not, or the specific criteria involved in just war theory, the more material fact is that war is an inescapable element of reality. We can argue whether past wars were justly declared and fought. We can even wonder if the motivations of individual combatants were grounded in just war theory or something else. The reality is that the relative peace, order and prosperity we enjoy today is the tectonic plate settlement that resulted from yesterday’s earth-shattering wars. It is entirely appropriate – it is necessary, indeed – to pay tribute to those who understood this reality, and paid the ultimate price for it.

I finish with one last element of Remembrance Day celebration, and that is the phrase “Lest We Forget.” This is the refrain of a poem by English writer Rudyard Kipling, written for the Diamond Jubilee of Queen Victoria in 1897. The origin of that refrain? The Bible – Deuteronomy 6:12, to be specific. I hope, pray, and act, that I may never forget.

Published: November 7, 2021