This monograph examines the vital role that operational sustainment plays in the application of critical elements of operational art and operational design. The operational art and sustainment issues examined in this monograph are assessed using the operational environments of Operation Restore Hope and Operation Uphold Democracy. This monograph concentrates on the military activity of campaigning. The operational level of war is conducted by operational commanders who organize, employ, and sustain campaigns in order to accomplish strategic aims. Determining time, location, and for what objective military forces will be utilized within a joint area of operation to attain strategic objectives is at the very core of operational art and operational design. Sustainment is a supporting function of operational art and operational design. Operational sustainment supports the commander in achieving unity of effort, flexibility, and opportunity in the execution and design of military campaigns.