This article investigates the Swedish government’s perception of the power and intentions of the Soviet Union and Russia during the period 1988–93. The aim is to explain why the Swedish government decided to abandon its policy of neutrality and started to support the building-up of security cooperation within the EU. This can be seen as a case of foreign policy change. On the basis of previous research on the foreign policy of small states, a theoretical framework consisting of three external factors – the power structure of the international system, the degree of tension and the threat posed by the closest great power toward the small state – is applied. It is concluded that all three factors were important for the change in Swedish foreign policy, but that their relative importance varied.