Based on more than three decades of observation, Robert Jervis concludes in this book that the very foundation of many social science theories - especially those in political science - are faulty. Taking insights from complexity theory as his point of departure, the author observes that we live in a world where things are interconnected, where unintended consequences of our actions are unavoidable and unpredictable, and where the total effect of behavior is not equal to the sum of individual actions.

Jervis draws on a wide range of human endeavors to illustrate the nature of these system effects. He shows how increasing airport security might actually cost lives, not save them, and how removing dead trees (ostensibly to give living trees more room) may damage the health of an entire forest.

Similarly, he highlights the interconnectedness of the political world as he describes how the Cold War played out and as he narrates the series of events - with their unintended consequences - that escalated into World War I.