" In the short term, he writes, there are clearly challenges, but over the long haul, he argues that diversity has a range of benefits for a society, and that the fragmentation and distrust can be overcome. It’s not an easy process, but in the end it’s “well worth the effort.” Putnam cites the integration of institutions like the U.S. Army as proof that diversity can work."
The point about the army is a particularly interesting one because they certainly are experts in integration and conformity, which hits back to my point in my previous comment as well.
The army life is not a good example; it is an intense, catalytic experience that accelerates and exaggerates processes that may not even appear in the real life. For many people their army buddies are the people they trust because they trusted their life to them, nothing like this happens for regular people.
It's not just the military in wartime though. My father was in the US Army in the late 1950s after the Korean ceasefire was signed but when they were still drafting soldiers to be deployed there. It was the first time he had any major interaction with African-Americans as they were rare in the small Northern town he grew up in. Serving alongside them and realizing that they weren't much different from himself was a significant experience for him.
