This article examines the role defence provision played in the relations between a prince and his estates in early modern Europe. Using the Duchy of Wurttemberg as an example, it illustrates why the question of defence proved so significant in shaping prince‐estate relations, and how the attitudes that it forced each to adopt reveal much about their differing aims and general outlook. The dominant group within the Wurttemberg estates rejected the duke's preferred solution to the defence question, a standing army, out of fear that its adoption would alter the duchy's traditional political structure. Maintenance of this traditional structure was essential to the defence of the dominant group's vested social and economic interests. The dukes considered a standing army an essential prerequisite to the achievement of their dynastic and political goals. The estates’ rejection of it made conflict unavoidable. Though the estates were successful in opposing ducal policies, their lack of an alternative solution illustrates the general point that estates were unable to develop their own concept to rival their ruler's ‘modernizing’ pretensions. Instead, they remained entrenched in their traditional values and were not able to develop into modern parliaments. In contrast to the princes, however, their outlook was essentially peaceful, because war meant change and change was to be avoided.