The Common-Sense Case for Pacifism By Bryan Caplan

I used to call myself an isolationist, but I recently realized that pacifist is a much better description of my position. All of the following definitions aptly describe what I believe:

pacifism: The doctrine that disputes (especially between countries) should be

settled without recourse to violence; the active opposition to such

violence, especially the refusal to take part in military action

settled without recourse to violence; the active opposition to such violence, especially the refusal to take part in military action pacifist: opposed to war

pacifist: one who loves, supports, or favors peace; one who is pro-peace

pacifist: An individual who disagrees with war on principle

Some definitions of pacifism specify opposition to all violence, even in self-defense, but these strike me as too broad. I’m a pacifist not because I oppose self-defense, but because it’s virtually impossible to fight a war of self-defense. Even if militaries don’t deliberately target innocent bystanders, they almost always wind up recklessly endangering their lives. If a policeman fought crime the way that “civilized” armies wage war, we’d put him in jail.

But isn’t pacifism, in Homer Simpson’s words, one of those views “with all the well-meaning rules that don’t work in real life”? No. Here’s my common-sense case for pacifism:

1. The immediate costs of war are clearly awful. Most wars lead to massive loss of life and wealth on at least one side. If you use a standard value of life of $5M, every 200,000 deaths is equivalent to a trillion dollars of damage.

2. The long-run benefits of war are highly uncertain. Some wars – most obviously the Napoleonic Wars and World War II – at least arguably deserve credit for decades of subsequent peace. But many other wars – like the French Revolution and World War I – just sowed the seeds for new and greater horrors. You could say, “Fine, let’s only fight wars with big long-run benefits.” In practice, however, it’s very difficult to predict a war’s long-run consequences. One of the great lessons of Tetlock’s Expert Political Judgment is that foreign policy experts are much more certain of their predictions than they have any right to be.

3. For a war to be morally justified, its long-run benefits have to be substantially larger than its short-run costs. I call this “the principle of mild deontology.” Almost everyone thinks it’s wrong to murder a random person and use his organs to save the lives of five other people. For a war to be morally justified, then, its (innocent lives saved/innocent lives lost) ratio would have to exceed 5:1. (I personally think that a much higher ratio is morally required, but I don’t need that assumption to make my case).

Are there conceivable circumstances under which I’d break my pacifist principles? Yes; as I explained in my debate with Robin Hanson, I oppose “one-sentence moral theories”:



It is absurd to latch on to an abstract grand

moral theory, and then defend it against every counter-example.

In the real-world, however, pacifism is a sound guide to action. While I admit that wars occasionally have good overall consequences, it’s very difficult to identify these wars in advance. And unless you’re willing to bite the bullet of involuntary organ donation, “good overall consequences” are insufficient to morally justify war. If the advocates of a war can’t reasonably claim that they’re saving five times as many innocent lives as they take, they’re in the wrong.

I suspect that economists’ main objection to pacifism is it actually increases the quantity of war by reducing the cost of aggression. As I’ve argued before, though, this is at best a half-truth:

Threats and bullying don’t just move along the “demand for crossing you” curve. If your targets perceive your behavior as inappropriate, mean, or downright evil, it shifts

their “demand for crossing you” out. Call it psychology, or just common

sense: People who previously bore you no ill will now start looking for

a chance to give you a taste of your own medicine. The upshot for foreign policy is that people who warn about “sowing

the seeds of hate” are not the simpletons they often seem to be.

Military reprisals against, for example, nations that harbor terrorists

reduce the quantity of terrorism holding anti-U.S. hatred fixed. But if

people in target countries and those who sympathize with them feel the

reprisals are unjustified, we are making them angrier and thereby

increasing the demand for terrorism. Net effect: Ambiguous.

Rebecca West once wrote that, “Feminism is the radical notion that women are people.” Pacifism, similarly, is the radical notion that before you kill innocent people, you should be reasonably sure that your action will have very good consequences. That’s a one-sentence moral theory even I’m comfortable embracing.