In a time of great need for Britain, a small coterie of influential businessmen gained access to secret information on industrial mobilisation as advisers to the Principal Supply Officers Committee. They provided the state with priceless advice, but, as "insiders" utilised their access to information to build a business empire at a fraction of the normal costs. Outsiders, in contrast, lacked influence and were forced together into a defensive "ring" - or cartel - which effectively fixed prices for British warships. By the 1930s, the cartel grew into one of the most sophisticated profiteering groups of its day. This book examines the relationship between the private naval armaments industry, businessmen, and the British government defence planners between the wars. It reassesses the concept of the military-industrial complex through the impact of disarmament upon private industry, the role of leading industrialists in supply and procurement policy, and the successes and failings of government organisation. It blends together political, naval, and business history in new ways, and, by situating the business activities of industrialists alongside their work as government advisors, sheds new light on the operation of the British state. This is the story of how these men profited while effectively saving the National Government from itself.