I also think the theory, that casual contact increases prejudice, conflicts with the tendency of racial conflicts to eventually resolve over long periods of time of several generations or more. Sometimes they’re resolved through genocide or racial expulsion, but in the modern period it seems like relaxation and eventual merger of the two particular races/ethnicities is more likely.
Maybe the way to make sense of this is that casual contact creates occasional “pockets” of intense interaction, where (for example) intermarriages and business relationships have effects similar to the military effects you describe – maybe not so much on the married couple/business partners who likely are less prejudiced, but in their immediate social circle.
And maybe short-term studies of casual contact miss some of these effects that happen rarely but lead to decreased prejudice.
Just guessing here….
Bonus Yglesias blogging wherein I quote myself: Matt thinks it's no big deal that potential Al Qaeda affiliates tried to contact Latin American drug dealers, because they failed. I think this is wrong, and part of the broader framework of the left wrongly thinking our porous borders are no big deal for national security. I babbled:
I’m going to somewhat disagree with Matt on this. If the African guys truly were Al Qaeda, then the incident shows an attempt, an attempt, by Al Qaeda to link to drug trafficking networks. That’s worrying because drug traffickers and immigrant smugglers have fairly effective systems of getting through US borders. It isn’t something to dismiss as unimportant.
Unfortunately, wingnuts on the right have grossly distorted and exaggerated it to serve their own loony interests on Cuba and Venezuela. It’s really a problem that one of our two political parties has no interest in actual, effective policy.