As far back as the 1980s when I served in the US military, officers were taught pretty much literally that diversity is strength. Because that's a practical, unavoidable truth in our all-volunteer military.

I went to high school in Iowa, and I had almost zero experience with Latino people, for example. That would not be likely for people growing up in Iowa today, but it was what it was.

When I joined the Marine Corp reserves and went to boot camp in San Diego as a 17-year-old, two of my five drill instructors were Latino, and so were many of my fellow recruits.

We all received diversity training (although they didn't call it that) pretty much immediately. How not? If we were going to be a cohesive unit, we all had to respect one another and get along. Because in that sense, diversity is literally strength.

Years later as an Air Force officer, my professional military education courses always — Every. Single. Course.— emphasized the military's critical need to foster respect for diversity. Because without that, our military would cease to be able to effectively function.

One of my courses was explicit about the fact that racial minorities are overrepresented in our all-volunteer military, and so small unit leaders must keep an eye out for racist problems
while rewarding respectful behavior and taking care to place respectful people in key positions of leadership.

They didn't call it DEI then. They called it institutional effectiveness, sometimes even framing it as existential.

I know this clown had to receive the same sort of training I did, but I guess he isn't smart enough (or can't set aside his racism enough) to have absorbed it.