John Major discusses an astonishing aspect of past Anglo-American history. All great powers have developed contingency plans for war with each other, and the United States in the early twentieth century was no exception. Each of Washington’s schemes was given a distinctive colour. Green mapped out intervention in neighbouring Mexico, Tan the occupation of the US protectorate in Cuba. Brown dealt with insurgency in America’s colony, the Philippines, Yellow mounted an expedition to China, Orange addressed a Pacific war with Japan. Plan Red orchestrated the American response to a showdown with Great Britain, or rather, with nothing less than the entire British Empire.