Hearts and Minds
I just watched the 1974 documentary "Hearts and Minds." It is a pretty powerful piece.
By the end, I had realized that there used to be a pretty good working definition of liberal: someone who had learned the lessons of Vietnam. That definition largely fell out of fashion at some point. (To be fair, so did liberalism itself.) In the 1980s, the favored terminology became "Vietnam Syndrome," Reagan's revisionist fiction that the U.S. would have won but for the treason of the DFHs.
As I watch Barack Obama prepare to send tens of thousands more troops to Afghanistan to support a corrupt and unpopular government, in support of vague and unconvincing strategic goals, eight years into a conflict with no end in sight, I feel forced to admit that he is not a liberal.