I listened to some of this and the guy has a British or Australian accent and appears to be slooooowwwwwwwly talking (singing) about a possible Vietnam experience.
I couldn’t handle listening to it to determine if it had a patriotic or a leftward tilt. It was poorly done.
Redgum were an Australian folk and political music group formed in Adelaide in 1975 by singer-songwriter John Schumann, Michael Atkinson on guitars/vocals, Verity Truman on flute/vocals; they were later joined by Hugh McDonald on fiddle and Chris Timms on violin.