This thesis explores the relationship between politics and new media in the context of digital diplomacy. In contrast to dominant mediatization approaches to politics that consider political logic to be dominated or even replaced by media logic, it develops a politics-centered approach where mediatization is considered an interinstitutional process. Using the case of the EU’s digital diplomacy, the thesis analyzes how practices of digital diplomacy have developed and are talked about among their practitioners. The conclusion is that mediatization of politics happens through an interaction of media logic and the hosting political context, where expectations, threats, leadership, resources, skills, learning, and individuals influence the practices where new media and diplomacy ultimately blends.