Explores how cognitive biases impact national security decision-making, particularly focusing on U.S. foreign policy. The book examines several historical cases, including Afghanistan and the Soviet invasion, the Iran-Contra affair, radical terrorism's worldview, and the 2003 invasion of Iraq, to illustrate how biases like overconfidence, confirmation bias, focusing illusion, and short-term thinking influence leaders' perceptions and actions. It also discusses the U.S. energy policy as a case study for short-term bias, and concludes by offering strategies to mitigate these cognitive errors for more effective decision-making. The overarching theme is the systematic deviation from rational thought in critical international relations contexts.