During the changes and troubles of the 20th century, officials in Britain faced a huge question: how could they maintain imperial power? Dr Louis Halewood has been researching the troubles faced by British policy makers, and the efforts to maintain dominance with their dominions and allies as Pax Britannica came to a close. In this episode he speaks to James from the University of Plymouth about the development of British naval power, and explores the role of the United States in this emerging world.