Euan Lloyd gained the idea for the film from events surrounding the siege of the Iranian embassy in London, most notably the storming of the building on 5 May 1980 by the SAS. Living just half a mile from the embassy, he visited it on multiple occasions during the four days it was occupied by terrorists, witnessing the dramatic ending to the siege in person. That same evening he called his lawyer in New York and asked him to register 5 titles with the Motion Picture Association of America, one of which was "SAS: Who Dares Wins". In a slightly abbreviated form, this became the name of the film based on the incident which he then set out to make.