The Outsider (1979)

Stars:

Craig Wasson, Sterling Hayden, Patricia Quinn

Idealistic Vietnam veteran Michael Flaherty (Wasson), enthralled by the stories told to him by his grandfather (Hayden) and disillusioned by the lack of a clear cut cause in Vietnam, leaves his comfortable life in a Detroit suburb and goes to Ireland to fight for the IRA, only to discover that nothing is ever clear cut.