Drawing primarily on the experience of the UK since 2001, this article examines the increasing prevalence of risk as an organizing concept for western defence and security planning and its implications for civil–military relations and strategy-making. It argues that there may be tensions between such approaches and the principles of good strategy-making, which aim to link means and resources to ends in a coherent manner. Not only does risk potentially blur the relationship between means and ends in the strategy-making process, it also exposes it to contestation, with multiple interpretations of what the risks actually are and the strategic priority (and commitment) which should be attached to them. The article examines these tensions at three levels of risk contestation for British defence: institutions, operations and military–society relations. In the case of the UK, it contends that the logic of risk has not been able to provide the same national motivation and sense of strategic purpose as the logic of threat. In this context, calls for a reinvigoration of traditional strategy-making or a renewed conception of national interest may be missing a more fundamental dissonance between defence policy, civil–military relations and the wider security context. More widely, the strategic ennui that some western states have been accused of may not simply be a product of somehow falling out of the habit of strategy-making or an absence of ‘political will’. Instead, it may reflect deeper social and geostrategic trends which constrain and complicate the use of military force and obscure its utility in the public imagination.