What drives individuals with conflicting and often opposing interests to come together and act in unison? The book explores how the fear of external threats shapes political groups during their formation and contributes to their maintenance, reinforcing their unity in times of crisis.

It develops the theory of "negative coalition," which examines the dynamics expressed by the adage "The enemy of my enemy is my friend," and subsequently outlines its role from ancient Greek and Roman political thought to Machiavelli and the theorists of state interest, as well as from Hobbes and his followers—along with their critics—to the proponents of political realism that prevailed in the 20th century.

By focusing on the role of fear and hostility in shaping the identity of individuals and groups, it highlights an important tradition in political thought and approaches well-known texts in an innovative way.

The book demonstrates that the fear of external threats is an essential element in the creation and maintenance of political groups, while its absence renders political coalition unsustainable.