Abstract Through an explanation of the domestic political controversy that surrounded the most recent Swedish candidature and subsequent membership of the UN Security Council 2017–18, this article contributes to our understanding of the domestic–foreign policy nexus in two respects. First, it conceptualizes a domain of foreign policy priorities. Issues within this domain are likelier to deviate from a consensual pattern of foreign policy by sparking conflict, as they provoke competing national role conceptions among the foreign policy elite. Second, it refines results from previous study on the executive–legislative relationship in foreign policy. It confirms the association between party conflict on substantive foreign policy and a higher level of parliamentary control on the government. The conflict on substance leads to a decline in trust among members of parliament in opposition, which may motivate the continuation of parliamentary control through available instruments also after the conflict on substance is settled. The analysis is conducted in three descriptive steps: (1) the domestic-institutional context of decision-making, (2) partisan divides, and (3) the executive–legislative relationship. It utilizes a variety of sources, including parliamentary debates, governmental and parliamentary assessments, and interviews with diplomats and senior officials.