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Common Tactical Concepts and Echelons 31 July 2019 ADP 3-90 2-3  The sustainment warfighting function is the related tasks and systems that provide support and services to ensure freedom of action, extend operational reach, and prolong endurance (ADP 3-0).  The protection warfighting function is the related tasks and systems that preserve the force so the commander can apply maximum combat power to accomplish the mission (ADP 3-0). The successful execution of operations requires the use of all the warfighting functions in various combinations and with the other two elements of combat power—leadership and information. Figure 2-1. Taxonomy of Army tactics