David Mason has served on operations as a French Foreign Legion paratrooper (about which he wrote a book titled Marching with the Devil), Australian Defence Civilian, private contractor, and Australian Defence Force Officer. He is a lawyer who was an Associate for a Supreme Court Judge, for a decade was Counsel, International Law in Defence Legal, Deputy Chief of Staff to a Defence Minister and National Security Adviser to the Attorney General of Australia. He is currently serving as a Legal Officer at HQJOC.