This paper builds conceptual and theoretical bridges between work on transnational politics in IR and sociology, and research on civil conflict and civil war. Students of civil war have come to recognize the central role played by transnationalism, documenting its importance with increasingly rich and disaggregated data sets and sophisticated methodological tools. However, such work is too often theoretically underspecified and ontologically hindered by a one-dimensional and atomistic view of human agency. In contrast, research on transnationalism, while richly theorized and ontologically plural, is hindered by methodological weaknesses and a serious problem of selection bias too often studying only the good things (human rights NGOs, global civil society) in world politics.In this paper, I take two central concepts and findings from work on transnationalism in IR - on norm diffusion and transnational community building (socialization) and explore how and whether they can be applied in situations of civil conflict. This exercise is not only theoretical, asking whether terms and concepts developed in one domain travel to another. Equally important, it is about methods and data. Work on socialization and norm diffusion has largely been conducted in settings where institutions work and the rule of law prevails. How can such concepts be operationalized in situations of civil conflict and war, where institutions have failed and there is no rule of law?