The author analyzes the impact of the war on terrorism and the requirements of the 2001 Quadrennial Defense Review on the many essential missions conducted by the U.S. Armed Forces. Focusing primarily on the Army, he highlights the requirements associated with combat operations against terrorists, accelerating transformation and the new emphasis on homeland security and force protection. At the same time, he points out that the Army and the other Services must remain involved worldwide in day-to-day assurance, dissuasion, and deterrence activities; execution of peace operations and other smaller-scale contingencies; and remaining ready for other major combat operations. The author asserts that these obligations require the Army to reshape and expand its force structure. Failure to do so places critical missions at risk around the world could lead to replacement of operational "victory" in the war on terrorism with strategic failure, as regional instability increases around the world.