As politicians at all levels debate paying black Americans "reparations" for chattel slavery, a careful study of the wealth gaps between ethnic groups shows that ethnic prejudice explains very little. Other factors matter more.
It's easy to see why many young people don't find military service especially enticing. The US military lost in Iraq and Afghanistan, and the usual regime propaganda may not be working anymore. But we'll only know the full extent of the "problem" once unemployment starts to go up.