Command and control in military operations constitute a complex web of interrelated cognitive activities and information processes. Today, the practice of command and control is affected by simultaneous social and technological changes. Intensified research is justified in order to conceive the nature of the practice, the changes, and develop relevant theories for future evolution.The purpose of the study is to generate theories, providing new insights in the traditional practices as the basis for continued research. In particular, we have studied coalition command and control during the UN operation in former Yugoslavia from the perspective of participating Swedish forces. We conduct a qualitative analysis of interview data, and apply a grounded theory approach within the paradigm of information systems research.We have found that constraint management, for instance physical, communicative, and social constraints, dominates the command and control activities. We describe the intense communication and personal interaction and clarify the interaction between informal procedures and the traditional formal structures and rules when constraints appear. The evolving grounded theory is a recognition of the non-orderly components within command and control.Based on the results of this study we suggest that support for constraint management, within information systems research, becomes the common framework for continued research on support for military command and control. This perspective affects the design of information systems, modelling efforts, and ultimately the doctrines for command and control. Hopefully our result will encourage cooperation between military practitioners, systems designers and researchers, and the development of adequate tools and techniques for the management of constraints and change in the military and elsewhere.