This article contends that the classic public diplomacy model prioritising scholarly research on maximising soft power in the eyes of foreign publics needs to be extended. It proposes a new concept, Negative Watch, which dyadically complements Nye’s in (Ann Am Acad Polit Soc Sci 616: 94–109, 2008) idea of soft power. By extending the epistemology surrounding negative place branding, this paper seeks to expand the debates around it. Where soft power is about accruing power via credibility, Negative Watch maps its loss, approaching it from a communicative dimension. Using a case study approach, the article presents the concept as a model with two key components (1) An index comprising a typology of unfavourable narratives connoting negative affect towards nation brands; (2) a heuristic model outlining a spectrum of outcomes precipitated by reputational decline. The index can be used as a self-assessment tool by a nation to track its reputational erosion, so that it may take measures before it progresses too far down the spectrum of consequences. It can also facilitate systemic assessment of external actors, including allies as well as adversaries, to facilitate strategic decision making within the realm of international relations and public diplomacy.