In "The March of Folly: From Troy to Vietnam," Barbara W. Tuchman explores the recurring theme of governments making decisions that are contrary to their own interests throughout history. The quote highlights the allure of theoretical events and ideas, but emphasizes the importance of understanding and learning from real historical occurrences. Tuchman asserts that while imagining potential scenarios can be intriguing, it is the actual actions taken by governments that define their legacies and impact their citizens.

Through various case studies, Tuchman illustrates how folly, especially in leadership, has often led to avoidable disasters. She examines several historical episodes where leaders have ignored rational advice and principles, pursuing misguided paths instead. This plea for historical comprehension serves as a reminder of the lessons that can be drawn from previous mistakes, urging contemporary leaders to reflect on the past in order to prevent repeating it.