Tactical success in combat does not of itself guarantee victory in war. What matters ultimately in war is strategic success: attainment of our political aims and the protection of our national interests. The operational level of war provides the linkage between tactics and strategy. It is the discipline of conceiving, focusing, and exploiting a variety of tactical actions to realize a strategic aim. With that thought as our point of departure, this publication discusses the intermediate, operational level of war and the military campaign which is the vehicle for organizing tactical actions to achieve strategic objectives.