This study examines veiled aggression in diplomatic language use from the point of view of speech acts. More specifically, we examine how the speech act of ‘Tell’ is used to realise aggression in a small corpus of diplomatic notes written between February and May 1844, exchanged between a US American and a Chinese diplomat. Tell, by default, presents a ‘neutral’ informative illocution. However, in contexts of diplomatic conflicts, particularly when a threat is made, realising Tell often helps the aggressor to deliver menacing messages under a veneer of civility. Tell is also often intertwined with other speech acts through which aggression is realised, such as Request and Complain. By modelling the aggressive function of Tell in the ritual genre of diplomatic notes, this paper fills a knowledge gap by studying aggression in a setting in which aggression operates within the boundaries of the ritual frame of a diplomatic genre.