A prime example that Waltz refers to is Lenin's theory of imperialism, which posits that the main cause of war is rooted in the need for capitalist states to continue opening up new markets to perpetuate their economic system at home.

A more familiar example in the Western world today is the notion that nondemocratic states, because of their internal composition, start wars.

In this context, "anarchy" is defined not as a condition of chaos or disorder but as one in which there is no sovereign body that governs the interactions between autonomous nation-states.

In other words, unlike in domestic society in which citizens can theoretically rely on law enforcement agencies to protect their persons and property, if a state is invaded and calls "911," it cannot be sure anyone will answer.

J. David Singer praised the book in a 1960 review, arguing that it was important for International Relations scholars to understand the assumptions behind their research.