The Unvanquished (film)

The Unvanquished French LInsoumis , literally Missing without leave is a 1964 film noir directed by Alain Cavalier and starring Alain Delon opposite Lea Massari.

Thomas Vlassenroot, a citizen of Luxembourg, after his divorce, decides to enlist in the French Foreign Legion. He is posted to Algeria but during the 1961 uprising he becomes disllusioned and deserts.While in hiding he receives a visit from his former lieutenant played by Georges Gret, who is also a defector but now works for the OAS, a group opposing Algerian independence.Lieutenant Fraser entices Thomas to join the OAS and also to take part in a plan to kidnap lawyer Dominique Servet by promising him enough money to enable him to return to his home in Luxembourg. ........

Source: Wikipedia