“There, we became intimately familiar with the humbling trials of war. We were lucky enough to build , train, and lead high-performance, winning teams that proved exceptionally effective. We saw, firsthand the perils of complacency, … We know what it means to fail — to lose, to be surprised, outmaneuvered, or simply beaten. Those lessons were the hardest, but perhaps the most important. We learned that leadership requires belief in the mission and unyielding perseverance to achieve victory, particularly when doubters question whether victory is even possible. As SEAL leaders, we developed, tested, confirmed, and captured an array of leadership lessons as well as management and organizational best practices.” WarLeadershipFailureVictoryEffectivenessLessons Learned Book:Extreme Ownership. Leadership Development Handbook. Source: Extreme Ownership. Leadership Development Handbook.