Real and imagined versions of the island and the microbe come together to tell a new story about geopolitical relations between two successive Anglophone empires: the British and the American. Bassam Sidiki assembles a vast archive of literary, cultural, and medical documents to argue that claims of British or American insularity are specious; these Anglophone empires have been economically, culturally, and scientifically interdependent since the turn of the century to the present as the British century gave way to the American. Ironically, the inter-imperial relations that refute imperial insularity are often most visible in island-like spaces such as gardens, ships, and brothels, and in actual tropical islands where the two imperial powers have worked together—or at odds—to hold infectious diseases at bay. Sidiki documents historical and imaginary representations of infectious diseases such as the plague, venereal disease, Spanish flu, and Hansen’s disease in the long twentieth century, and how these diseases brought the British and US empires into simultaneous collaboration and competition across the Anglophone world. “Sidiki brilliantly contextualizes the uses of a certain medicalized figure of the 'parasite' within American and British imperial history, while his careful storytelling and eye for the compelling anecdote makes his complex ideas lucid and engaging.”—Pamela Gilbert, author of Victorian Skin: Surface, Self, History No empire is an island Bassam Sidiki is assistant professor of English at the University of Texas at Austin.