A showing of Indian director Mira Nair\'s \"The Reluctant Fundamentalist\" opened the fourth Doha Tribeca Film Festival on Saturday, with US actor Robert De Niro in attendance. The film tackles the sensitive issue of relations between Islam and the West through the dilemma of a young Pakistani Harvard graduate and Wall Street trader who struggles to reconcile pursuit of the American dream and his Muslim roots. \"The Reluctant Fundamentalist,\" which received funding from the Doha Film Institute, also opened the Venice festival in July. Nair won the Venice Golden Lion award for her 2001 drama \"Monsoon Wedding.\" The Tribeca Film Festival in New York, co-founded by De Niro to revitalise Manhattan\'s cultural life after the September 11 2001 attacks, teamed up with Qatar to organise the fourth annual Doha festival. Two other films dealing with radical Islamism are among the 27 being shown -- Moroccan Nabil Ayouch\'s \"Horses of God,\" centring on the 2003 Casablanca bombings, and French-Algerian Merzak Allouache\'s \"The Repentant,\" about a jihadist who leaves his hideout to return home.