1-1. War is a lethal clash of wills and an inherently human endeavor that requires perseverance, sacrifice, and tenacity. The United States Army’s primary reason for existence is to conduct large-scale combat operations for as long as is required to prevail as part of the joint force. Army leaders provide purpose, direction, and motivation required to endure the physical hardship, privation, and danger of combat. Army leaders inspire others to risk their lives to accomplish missions of importance to the Nation. All the other contexts where leaders exercise leadership daily ensure the Army is prepared to do what the Nation requires.