Taking the foreign fighter phenomenon as its example, this chapter critically discusses the relative exclusion of the role of violence in scholarly approaches to modern subjectivity formation. It suggests research strategies, which include violence in our understanding of the rise of the modern subject. The formation of modern subjectivities is related to socially accepted representations of meaningful selfhoods. These social imaginaries serve as points of reference for individual identity constructions. According to the hegemonic liberal imaginary of the emancipation of a reflexive, rational, self-interested and expressive modern individual, subjectivity formation is supposed to take place in a pacified world. Yet, the twentieth century witnessed a continuing series of wars and violent conflicts, which do not correspond to this liberal imaginary. Why this neglect of violence in modern subjectivity formation? How does the violent “other” challenge the liberal narrative? In light of the ambiguity between war and modernity, this chapter compares the foreign fighter phenomenon in contemporary Syria with the civil war in Spain (1936–1939), where the recruitment of foreign fighters contributed to the escalation of local conflicts into brutal wars with global connotations.