How well commanders can react and adapt to the unfolding of unforeseen events is itself a dimension of good planning; flexibility rests with clearly knowing the options for handling various eventualities. Obviously the list of considerations is a long one. Since military historians strive to understand their subject better and military professionals constantly work to expand their knowledge of military art, both struggle with the difficulties surrounding military planning. It is natural, therefore, for them to address the topic jointly in a professional meeting. The best way to accomplish these aims, however, is not clear because the problems inherent in military planning are many and involved. This volume features one approach taken by those participating in the 1984 Eleventh Military History Symposium and makes no pretension to exhaustive treatment. It does, however, strive to provide key insights into recent military planning experiences that will be of value to planners. If it serves to stimulate and inform those entrusted with the difficult burden of planning, it will have succeeded in the real sense.