Weale was born in Knightsbridge, London. Prior to becoming a professional author, he served as an officer in the British Army Intelligence Corps. He was compulsorily mobilised for active service in Iraq in May 2003 and from July to December 2003 held the appointment of Deputy Governor of Dhi Qar province in southern Iraq, seconded from the staff of Multi-National Division (South-East) (Iraq) to the Coalition Provisional Authority. From September 2003 he supervised a number of democratic local elections in towns in Dhi Qar province – the first to be held in Iraq – as well as co-ordinating reconstruction projects and liaising with Coalition security forces. He was succeeded in this role – after an interregnum – by Rory Stewart.
One of his books, Renegades: Hitler's Englishmen gives a detailed account of British traitors and collaborators during World War II, including William Joyce, John Amery and the British Free Corps.