Mearsheimer introduces the concept of offensive realism, which posits that great powers are inherently aggressive and seek to dominate their rivals. This theory challenges the notion that states can achieve lasting peace through cooperation and diplomacy. Instead, Mearsheimer argues that the anarchic nature of the international system compels states to pursue power to ensure their survival.

One of the central themes of the book is the inevitability of conflict among great powers. Mearsheimer contends that as long as the international system remains anarchic, great powers will continue to compete for dominance. This competition often leads to conflicts, as states are driven by the need to secure their position and prevent rivals from gaining too much power.

Mearsheimer provides a detailed analysis of China's rise and its implications for global politics. He argues that China's growing economic and military power will inevitably lead to tensions with the United States, which seeks to maintain its status as the world's sole regional hegemon. According to Mearsheimer, this dynamic will likely result in increased competition and potential conflict between the two superpowers.