Surveys suggest that as many as 80% of those who serve come from a family in which a parent or sibling is also in the military. They often live in relative isolation — behind the gates of military installations such as Ft. Bragg or in the deeply military communities like Fayetteville, N.C., that surround them.

The segregation is so pronounced that it can be traced on a map: Some 49% of the 1.3 million active-duty service members in the U.S. are concentrated in just five states — California, Virginia, Texas, North Carolina and Georgia.

The U.S. military today is gradually becoming a separate warrior class, many analysts say, that is becoming increasingly distinct from the public it is charged with protecting. 

As the size of the military shrinks, the connections between military personnel and the broad civilian population appear to be growing more distant, the Pew Research Center concluded after a broad 2012 study of both service members and civilians.