Intelligence services form an important but controversial part of the modern state. Drawing mainly on British and American examples, this book provides an analytic framework for understanding the "intelligence community" and assessing its value. Michael Herman, a former senior British Intelligence officer, describes the various components of intelligence; discusses what intelligence is for; considers issues of accuracy, evaluation and efficiency; and makes recommendations for the future of intelligence in the post-Cold War world.
I read this for a class, it is really USA based. And not relevant to now. It is more the history from intelligence and how it helped in the cold war en wars before that.