In the thick of the Vietnam conflict back in 1968, only one movie honcho had the brass to put his views, however crackers, right up there on the screen. I'm talking about the dove-baiting Duke himself, John Wayne. As the star and director of The Green Berets, the right-wing Wayne attempted to give this undeclared war what the government could not: the good-guy-bad-guy clarity of a western. Liberal Hollywood justifiably derided the Duke but gutlessly offered no film alternative. Vietnam was moral…