This study examines whether Russian influence operations based on reflexive control affected Swedish decisions on the first military support package to Ukraine during the period from summer 2021 to February 2022. The research applies a theory-testing case study design using process tracing. Two competing explanatory models are assessed: external influence through Russian reflexive control and domestic constraints derived from legal and regulatory arms export frameworks. The empirical material consists of official documents, public statements and incident reporting. The findings show that Sweden was subjected to Russian reflexive control and that this influence shaped the security policy context of the decision. However, neither Russian influence nor legal restrictions on arms exports can, with sufficient certainty, explain the scope of Sweden’s first military support package to Ukraine. Rather, the decision appears to have emerged from the interaction of several factors rather than a single dominant cause.