David Mason is a former French Foreign Legion paratrooper who has served on operations as an Australian Defence Force Officer, an Australian Defence Civilian, and a private contractor. He has served in Africa, the Pacific and the Middle East. He has been Deputy Chief of Staff to an Australian Defence Minister and National Security Adviser to the Attorney-General. He is a lawyer specialising in the Laws of War and a Reserve Lieutenant Colonel in the Australian Army Legal Corps who formerly held the role of Counsel, International Law, in the Australian Department of Defence. He is a Barrister of the High Court of Australia.