This book argues that organizations improve decision-making and reduce catastrophic failures by deliberately adopting adversarial, outsider perspectives to challenge assumptions, expose blind spots and overcome groupthink; drawing on historical case studies and operational lessons from military, intelligence, and corporate settings, it explains how structured “red teaming” (war-gaming, penetration testing, devil’s advocacy and other skeptical methods) uncovers vulnerabilities, why institutions resist such scrutiny, and offers practical recommendations for institutionalizing independent, critical testing to produce more resilient policies and plans.