This manual sets forth the basic concepts of US Army doctrine. These concepts form the foundation for what is taught in our service schools, and the guide for training and combat development throughout the Army. Most important, this manual presents principles for accomplishing the Army's primary mission winning the land battle. FM 100-5, the capstone of the Army's system of field manuals, covers the relationships among operations. Details of those operations are described in other manuals. This manual is intended for use by commanders and trainers at all echelons.