This dissertation contributes to the growing literature on conflict-related sexual violence (CRSV). More specifically, the four essays it contains advance our understanding of CRSV by shedding light on the intersection between international involvement and CRSV perpetrated by states and rebel groups engaged in civil war. Despite the increased attention to CRSV among international policy-makers, this intersection has been examined only sparsely within the scholarship on CRSV. Essays I, II, and III address the overarching question of how different types of international involvement influence the level of CRSV. Essay I offers a global study of the effect of third-party military involvement on levels of CRSV. It argues that shifts in the balance of power following external involvement tend to aggravate the situation with regard to CRSV, and it finds indicative support for this. Essay II examines the capacity of peacekeeping missions to mitigate CRSV. It finds that the effectiveness of peacekeeping hinges on the degree of internal control exercised by states and rebel groups. Essay III looks beyond military involvement and focuses on the political power of condemnation. Using newly collected data on condemnations of sexual violence issued by the United Nations (UN) human-rights body between 1987 and 2014, the study tests the extent to which governments that perpetrate CRSV can be influenced by international condemnation. In parallel, the study examines the power of domestic outrage expressed through protests. The findings have important policy implications: Domestic protests are associated with an escalation of CRSV by states. International condemnation correlates with declines in CRSV in recent years (2008–2014), but not historically. International involvement – whether multilateral or unilateral – only materialises if fellow states so decide. Essay IV thus focuses on the willingness of states to take action against CRSV perpetrated by other states. By examining bilateral condemnations of sexual violence issued within the UN Universal Periodic Review, this essay sheds light on the diplomatic relationships and political interests that shape the (un)willingness of individual states to condemn CRSV. In sum, this dissertation makes both theoretical and empirical contributions to the research on CRSV, as well as to the scholarship on international involvement in civil wars more broadly.