An in-depth case study of lessons learned, using modeling and simulation in the area of National Missile Defense Command and Control (NMD C2), so that future NMD commanders and staff can visualize their roles in the oversight of a complex, largely automated system is presented. Models and simulations are described which have been used to portray the operation of the automated software algorithms for battle planning and management, and how control actions and intervention by human operators during a missile engagement positively or negatively effect overall system performance. Finally, the successes and challenges encountered when trying to develop system metaphors using models and simulations are described in the context of future modeling and simulation plans for NMD.