Focusing on British involvement in the 1960s Yemen Civil War, this article examines the centralised mechanisms developed in Whitehall to coordinate covert action interdepartmentally. It therefore sheds new light on London’s security and intelligence machine and its input into clandestine operations. Drawing on recently declassified documents and interviews, it uncovers various important but secretive actors, which have been overlooked or misunderstood in the existing literature, and outlines their functions in the most detail yet available. In doing so, it considers how these bodies evolved in relation to competing threat assessments of the local situation and the impact they had on Britain’s covert intervention in the theatre. This article assesses the utility of the system and argues that it provided an effective means to ensure that any covert action sanctioned was properly scrutinised so as to reduce risks and best meet national interests.