The aim of this chapter is to identify and scrutinize the mechanisms of overt and covert argumentation and counter-argumentation that underlie the question-answer turn-taking structure in a political accountability interview conducted as part of the BBC HARDtalk programmes. The political accountability interview ( Montgomery, 2011 ) can be regarded as an interviewer-mediated hybrid dialogue genre that combines inquiry dialogue and persuasion dialogue in varying degrees. As an inquiry dialogue it exhibits a question-and-answer pattern of information-seeking and information-sharing, and as a persuasion dialogue it functions as a consistent pursuit on either side to advance argumentation-supported interpretations and evaluations of targeted facts and events. While an interviewer is normally supposed to assume a neutral and impartial role in questioning the interviewee, there is increasing evidence ( Bell & van Leeuven, 1994 ; Clayman, 2002 ; Heritage, 2002 ) that during the interview interaction, both interviewer and interviewee compete to assume control over meaning negotiation about the (re)interpretation and (re)contextualisation of controversial issues under discussion in order to impact the perceptions and beliefs of a multi-layered and diverse audience. The analytical focus of the present investigation is twofold: on the one hand, the interplay of questions and answers used by the interviewer and the interviewee to articulate argumentative and counter-argumentative claims meant to legitimize or delegitimize the relevance and validity of debated standpoints in an interview about controversial political events (Russian interventions in Ukraine) and related international reactions; on the other hand, the argumentation strategies used by the interviewer and the interviewee to justify or to challenge the relevance and validity of competing definitions and (re)definitions of keywords central to the discussion.