> The people who promote wars frequently try to cast the enemy as alien, in order to rile up support for the war and to get soldiers to participate.
I'd argue that the cultural perception of the belligerent humans towards their targets is far more important than objective differences.
And you and parent are certainly being overly-reductive compared to the context of the times.
What would a 1930s German have said about being compared to a Polish or Dutch person? Would they have seen themselves as "pretty similar"?
And I'm not sure how many Indians and Pakistanis you've talked to, but they're pretty close to space aliens to each other.
Same with Shia Iraqis and Sunni Iraqis, and both with Kurds. Etc etc.
I don't see how you can say "these peoples are the same" across any modern ethnic or national boundaries without a lot more support without it coming across as "those people all look alike."
Hell, I can localize most folks in the US within five sentences or so.
And yes, there were states that straddled the Mason-Dixon line (and states like Virginia that were shattered because of it), but outside of those limited cases I'm sure the majority of the people involved could have identified "the other" pretty easily.
Point being that if we're finely tuned enough to physical and cultural differences amongst our own species, yet still war on those we can perceive as different... imagine how much stronger that impulse would be against something that didn't even look like us.
My point was as a direct counter to your assertion that warfare increases with degree of difference between peoples.
That would predict that the Germans would prefer to ally with other Europeans against people like the Japanese, who they are maximally different from. Historically this did not happen. Yes, there are clear conflicts between each of the groups named, but they are more similar to each other than they are to most other populations of humans.
Let's say an alien combat spacecraft crash-lands in the middle of ISIS-controlled territory. Would you expect ISIS to immediately declare a cease-fire and surrender the craft and its weaponry to the UN so that humanity can work together to face this new threat, or do you think they would immediately go about using it as a tool to better murder their fellow humans?
If you're proceeding purely from history, it's not supportive to say that armies on opposite sides of the world fight each other more rarely than armies next to each other.
A more apt test of my assertion would be the frequency with which civil wars (excluding cross-ethnic wars in poly-ethnic societies) are initiated vs non-civil wars (allowing for the variance caused by internal policing, international politics, etc).
Just because Poles and Germans are similar to you doesn't mean they're similar to each other.
On the latter, I'd prefer a more fair: ISIS and a non-ISIS armed force are engaged in a firefight. An alien ship crash lands and disembarks five non-humanoid aliens. These aliens immediately begin shooting at both parties. What happens?
@ethbro: I'd expect anyone who fires on any side on a battlefield to receive return fire. That hypothetical entirely disposes of "alienness" as a variable.
In any case, I've been trying to argue a point on my own rather than being a Scott Alexander repost-bot, but I have clearly failed. Most of what I'm getting at is based on what I remember from http://slatestarcodex.com/2014/09/30/i-can-tolerate-anything... . He presents this far better than I have.
I'd argue that the cultural perception of the belligerent humans towards their targets is far more important than objective differences.
And you and parent are certainly being overly-reductive compared to the context of the times.
What would a 1930s German have said about being compared to a Polish or Dutch person? Would they have seen themselves as "pretty similar"?
And I'm not sure how many Indians and Pakistanis you've talked to, but they're pretty close to space aliens to each other.
Same with Shia Iraqis and Sunni Iraqis, and both with Kurds. Etc etc.
I don't see how you can say "these peoples are the same" across any modern ethnic or national boundaries without a lot more support without it coming across as "those people all look alike."
Hell, I can localize most folks in the US within five sentences or so.
And yes, there were states that straddled the Mason-Dixon line (and states like Virginia that were shattered because of it), but outside of those limited cases I'm sure the majority of the people involved could have identified "the other" pretty easily.
Point being that if we're finely tuned enough to physical and cultural differences amongst our own species, yet still war on those we can perceive as different... imagine how much stronger that impulse would be against something that didn't even look like us.