Given its eminent topicality, it's a shame David Zeiger' portrait of Vietnam veteran anti-war protesters doesn' pack more of a punch. Attempting to debunk the myth o returning soldiers being spat on by unsympathetic hippies Zeiger bypasses all sense of mixed emotions, in part becaus his subjects are by now reconciled to whatever conflicts the might have felt. Vintage footage from the landmark Winter Soldier (newly arrived on DVD) fills in some gaps, but only highlights the shortcomings of Zeiger's attempt. Also excerpted is the hard-to-find FTA, a document of the anti-USO tour that a softballed Jane Fonda fondly recalls. (Her son, Troy Garity, serves as the new film's narrator.) Historically intriguing but dramatically inert, Sir! No Sir! inadvertently minimizes the risks its subjects took by presenting them as a fait accompli.