The beheading of US journalist James Foley has shown the wider threat posed by Isis. But combating the Islamist group may involve some striking policy reversals for the west. The FT's Fred Studemann discusses the west’s options with Royal United Services Institute’s Afzal Ashraf and FT leader writer James Blitz.
Produced by Nalini Sivathasan. Filmed by Nicola Stansfield and Petros Gioumpasis.