One of the most important objectives of military intelligence is to warn of potential or immediate threats. This paper investigates several related research issues. First, what kinds of data can military space provide, with which to watch, monitor, and analyze hostile forces? Second, what operational mechanisms can work to integrate military intelligence, surveillance, and reconnaissance? Third, how can a system architecture in support of intelligence operations be implemented for decision support and knowledge management? The paper investigates how research work can contribute a system concept with military space applications to national defense and security. It investigates the use of a geographical information system as a system platform for integrating the spatial database, attribute database, rule base, case base and knowledge repository as a knowledge-based decision support system. A hypothetical case showing how the system is implemented is presented.