An active learning approach to the study of US national security decision making decision making can be achieved through the use of an in-class role-playing simulation. This article considers the importance of solid foundations for simulation design: (1) simulation preparation should be linked to class materials and learning outcomes, but also stand on its own; and (2) success in mirroring reality requires a careful, even rigid, simulation structure. This article also provides a methodology for assessing the simulation's impact on two separate issues: (1) student knowledge of the national security interagency process (based on a knowledge quiz given three times during the semester); and (2) student perception of the difficulty of making of national security decisions (based on a questionnaire given three times during the semester). Students were assigned roles within the national security bureaucracy, and presented with a challenge--the possibility of large-scale Iranian intervention in the Syrian Civil War. The assessment of student knowledge is still a work in process, complicated by logistical factors. The assessment of student perceptions of difficulty of decision making, however, yielded interesting preliminary results that should be replicated to make any conclusions more robust: Students began the course with a perception that national security decision making is highly complicated and difficult. Following lectures and readings, the perception of difficulty decreased significantly. However, the simulation increased student perception of decision making difficulty close to its original level. These results suggest that simulations are important for capturing complexities within decision making that lectures alone cannot.