Abstract: It is widely recognised that information technology will create a case for changes in the structure and function of the command chain. The most radical projections involve flattened command hierarchies and drastic decentralisation of decision- making responsibility. Others have argued that the special requirements of the military environment will continue to necessitate commander-subordinate relations that are not much different from those of today. This paper sheds light on the issue by presenting a mathematical model of the relationships between information technology, command centralisation, unity of purpose and operational complexity. It suggests that the operational paradigm has been evolving in a consistent direction over a period of many centuries, and that future adaptations due to digitisation can be understood in the same context. This involves a continuing emphasis, at each command layer, on the human and moral function of leadership, but a steady movement downwards of administrative and managerial activity.