This article describes how external changes, doctrines, personnel, organization and technology have interacted over time. Based on Swedish government terms in office from 1991 to present time, we give a general overview of some important changes in the international development and their influence on defence policy reports, defence policy bills and on the Swedish Armed Forces capability development. We use two approaches, demand pull and technology push, to describe the changes observed. Among external changes, the ongoing technology development is important. In order to meet the challenges of the future, we propose that the Swedish Armed Forces should increase their investments on research and development as well as on technology forecasting.