My guest this week is the writer and filmmaker Tom Petch, author of Speed, Aggression, Surprise: The Untold Secret Origins of the SAS. It’s predominantly the story of Dudley Clarke, played by Dominic West in SAS Rogue Heroes. Clarke was the brains behind so many Special Forces units that sprung up in the War – necessity being the mother of invention. We talk about him, Eric Dorman Smith, T.E. Lawrence and the modern day SAS.

Tom is also a filmmaker, and directed The Patrol, a psychological drama about a platoon of British troops up against the Taliban, so we talk a bit about that and the West’s withdrawal from Afghanistan.