Another Pew report, which complicates this earlier one, finds that more than three-quarters (77%) of adults over 50 said they have an immediate family member who served in the military; among people between 18-29 years old, the number is only one-third. Mary Dudziak discusses the political implications: 

As Americans become more isolated from the costs of war, military engagement no longer seems to require the support of the American people. Their disengagement does not limit the reach of American military action, but enables its expansion.

Stephen Bainbridge is reminded of Byron Farwell's history of Queen Victoria's "little wars": 

The British public paid almost no attention to the pervasive little wars: "Even at the time, punitive excursions, field forces, and minor expeditions were so commonplace that most Britons never knew of them." … The USA increasingly wages continuous warfare with decreasing political checks on Presidential power. It's like we've become a country of neo-Victorians. …  I can't help but recall that the era of Britain's little wars ended with the catastrophe of World War I.