The underlying problem is that so few Americans have any real contact with the military. From 1941 until 1973, the U.S. had a military draft. Not everybody served, but everybody had relatives, friends, classmates and neighbors who served. Everyone had an immediate interest in military policy and affairs. And all those people who actually served in the military, particularly the draftees, came home with inside knowledge of how the military worked, and real skepticism about some of its activities.
Today, one commentator said you would have to knock on 150 random doors to find a house where somebody was in the military. For most of us, the military is a foreign country. We say "Thank you for your service," and under our breath we say "Glad it's not me!" People who join the military are a self-selected group, mostly aspiring working-class, that stands apart from most Americans.
It's inconceivable that we would have gone to war in Iraq and Afghanistan or would be as overextended as we are around the world if there was a military draft today, and rich kids were getting pulled out of Ivy League colleges and shipped to the Sandbox -- and coming home in boxes.