Military history is full of incidents wherein a smaller army having a good knowledge of the terrain has defeated a much larger well-equipped and organized army. Nearly, all military activities depend on terrain relief and need careful planning and reconnaissance to ensure success. However, planning of military operations is a complex process and is guided by the experience and capability of the commander and his staff who provide him with the necessary and accurate information. The objective of this research is to provide real time access to the intelligence and geographic information produced by the other mission areas in a highly visual setting. Decision Maker Support (DMS) tool can be effectively used to make accurate decision for site selection. This decision making process can be made intelligent by developing GIS decision maker support system. In this paper, a spatial modeler has been used to produce a number of thematic maps useful for various military operations. The approach developed is capable of taking inputs in the form of data layers that may be generated from satellite images, aerial photographs, topographical maps or other ancillary data. Some common military operations such as selection of sites for small military camps, helipads, identification of tactically important roads and vehicle mobility movement are considered. The development of such spatial modeler decision maker shall tremendously assist the military commander to provide efficient and real-time information in an organized way for any military task.