Old Movies

A friend who is now a history professor brought this up years ago: what was the cultural phenomenon that produced the "Army" characters in old movies? Unlike today, where military types on film are one-dimensional, barking little dictators, who can always be counted on by us, the viewers, to do something insanely brutal and self-destructive, there was a brief time in American cinema where the Army characters were the good guys. More than that, actually--because to be "good" then, as now, often merely meant being "American"--they were well-educated, smart guys, who had the interests of humanity as they understood it, from their educations in philosophy and the humanities, at heart. What happened to THAT idea? It would be easier to believe the link between patriotism and militarism existed if that image endured. Where did it go? How far have we come/gone?