Ashley, author of The British Empire at War and several works on British colonialism, takes a hard look at the role of Britain's colonies in imperial defense, that is the nearly 50 crown colonies, protectorates, mandates, and other dependencies that were not parts of Britain, the Dominions, or India, such as Kenya, Bermuda, Ceylon, Bechuanaland, Mauritius, Malta, and the others, throwing fresh light on the surprisingly important role of the colonies in imperial defense.

Ashley notes that these entities often had distinct roles in the Empire. Some had for generations provided strategic bases, logistical support, and even manpower, for labor service or combat, in support of Imperial defense, as well, in earlier times, for imperial expansion, while others were only occasionally called upon to provide support. A brief discussion follows as to how Britain came to acquire many of these places, and their early roles in imperial defense. Then, in a series of case studies focused on a few colonies -- Ceylon, Mauritius, Bechuanaland, and a some others -- he takes a deeper look at colonial efforts during the world wars, particularly World War II. He then surveys the role of the colonies in the diminishing empire in the post-war era. Ashley often provides useful analysis of the motives of the "native" peoples in supporting the Empire, such as protection from countries likely be worse masters than Britain or economic benefit or the acquisition of political capital for the future, which in several areas was during he age of decolonialization. And he makes an impressive case that the colonies played a vital role in sustaining the empire: by 1945 more than 500,000 colonial troops were under arms, despite the loss of extensive territories in the Far East to the Japanese. 

A good book for anyone interested in the British empire or the world wars.