Since the 60′s two unifying forces, for good or ill, were removed from the country: the removal of Judeo/Christian values as the semi-official moral code of the public schools) and the death of the draft/aka Vietnam. (actually ending in the 70′s). These two changes had one thing in common, it took two generations for them to have the following effect:
It is now unlikely that a student going to school today, had a teacher or parent who 1. Served in the military or 2. Was taught that moral code in school. To a whole generation now being born these are things that belong to outsiders. This makes the military and religious people outsiders and strange to one group and vice versa. Since the military draws predominantly from those two groups it will become more isolated from the rest of the public as time goes by.
Very interesting perspective worth reading over at Datechguy.