One of my early motivations for studying the morality of war in contrast to the morality of peace (or, “everyday morality”) was that war has been around for a long time , and has long been tied to intragroup cooperation .
So, to the extent that we have reliable intuitions about harm in general, I thought that we might have reliable, but different, intuitions about harm in war.
There might even be an evolutionary basis for some of these intuitions, some precursors of (war) morality might be biologically encoded, and have adaptive functions .
Of course, I also thought (and think!) there might be cross-cultural differences in the morality of war – Haidt uses an analogy of taste for morality, which I find useful. Basically, even if the structures and functions of taste buds are the same all around the world, different cultures nonetheless develop different cuisines and preferences based on local conditions .
One aspect of “the morality of war” which I think might be fairly constant and universal, is the idea of limits on the conduct of war: who should and shouldn’t be killed? It seems like whenever and wherever “codes of conduct” for war emerge, they include some protections for the weak, young, and innocent . (Discussions with Luke have made me think differently about this “principle of discrimination”, but still…)
But we don’t only have intuitions about conduct of war – what’s being done in war – we also have intuitions about when it’s appropriate (or not) to go to war in the first place. In a bunch of studies, I have found that U.S. MTurk workers have pretty reliable intuitions about this aspect too . They think that wars of conquest are relatively unjust, while wars of defense are relatively just, including wars to defend other countries (i.e. military humanitarian interventions).
If you’d asked me before I ran those studies what I would have expected, I probably would not have guessed that this would be quite such a robust finding. (Doesn’t “might make right”? And what about the realist position of “war as politics by another means”?) And I still would not claim that this finding is universal, although until recently I probably would have said that I expected that it’s an intuition with a long history, perhaps stretching back to the middle ages when various (religious) leaders and thinkers were trying to work out how they could best justify their wars .
But then, this War on the Rocks podcast made me rethink things: the (legal) prohibition on wars of conquest seems to be a much more recent invention, coming into force only in 1945 (after being conceived in 1928). This brings us back to the relationship between law and morality again, as well as the question of to what extent morality matters (or not) in international relations, but… the point here is just that if I could go back “only” a 100 years, my MTurkers might have responded quite differently, perhaps partly because of changes to the legal frameworks around war.
Last week, an article called Cultural Change Over Time: Why Replicability Should Not Be the Gold Standard in Psychological Science made the rounds on Twitter. As a post hoc, convenient, justification of failures to replicate, it was roundly denounced. However, as just a general comment, it did remind me of the importance of spelling out all-of-the-above, as relevant, in the papers I write about war.
For example, I have a paper under review with Brock [pre-print] on the effect of war commemorations on support for war. The war commemoration we focused on is general (i.e. not WWII vs Vietnam, for example), and the participants are U.S. residents – and I totally think those details matter ! If the effect ends up being replicated (by myself, most likely?) I hope the project will also include an extension: to other wars, and to other cultures .
While war is old, it’s not invariable  – which is yet another motivation for studying it. Actually, it doesn’t really make sense to see change as neither a threat nor an excuse, given how constant it is! But we do probably need to get better at discussing our expectations for what will and won’t change. Consider this a note-to-self, and I’ll keep you updated.
 See, e.g. Thucydides’ History of the Peloponnesian War.[top]
 I’m being deliberately hand-wavy, but here are a few intriguing papers about this.[top]
 See the introduction to Haidt’s book The Righteous Mind, for example.[top]
 That’s what David Traven argues in his thesis and here, at least.[top]
 Still working on this paper – will let you know when the pre-print is ready![top]
 The Internet Encyclopedia of Philosophy has a great overview of (the history of) just war theory, but my intuition about historical justifications for war has probably been influenced by multiple sources…[top]
 As Mark also pointed out – thank you![top]
 This paper on associations people have with their national flags is totally inspiring in that regard.[top]
 This article and this one both touch on this – and I’m sure there’s more to be said too.[top]