This thesis is an examination of the role of elite media entities during periods of critical political engagement between one or more parties in moments of international crisis. The aim of this study is to extrapolate, from a close analysis of a case study, the role that such outlets can play in legitimising or, conversely, delegitimising the political actions of governments. To this end, a comparative analysis is conducted of American and Iranian editorials published over the critical period of negotiations to secure the Joint Comprehensive Plan of Action (JCPOA), an accord between a group of countries and the Islamic Republic of Iran concerning the latter’s nuclear programme, through the lens of Hall’s Representation theory and Teun A. van Dijk’s Critical Discourse Analysis approach. Editorial opinion has been selected due to the unique role it can play in reinforcing narratives that align with the normative line of the publication and its political constituency. The research indicates that highly contrasting modes of legitimation and representation in American and Iranian editorialisation – seen especially in different textual and contextual modes of discourse – have informed each nation’s characterisation of the other. In the case of US media, meaning is created through rhetorical argumentation, whereas the dominant discursive practices in Iranian media are more closely associated with storytelling. In conclusion, the case is made that a ‘third factor’ – i.e. states – in the process of representation, beyond the core modalities theorised by Hall, should be considered to be present in the texts.