Army Techniques Publication (ATP) 3-91, Division Operations, supports Doctrine 2015. ATP 3-91 expands on the doctrine and tactics contained in field manual (FM) 3-94. ATP 3-91 makes numerous changes from the obsolete 1996 edition of FM 71-100. The most significant change is the introduction of unified land operations as the Army's operational concept. The doctrine of unified land operations describes how the Army demonstrates its core competencies of combined arms maneuver and wide area security through three elements of decisive action-offense, defense, and stability.