This article examines what academic open letters about the Israel-Gaza war do communicatively: what purposes they serve as a genre, why they generate discord, and how their effects diverge from their aims of informing publics or influencing policy. It analyses 23 open letters published between October 2023 and early 2024, selected as representative of the conflict's initial phase. The article combines rhetoric - addressing genre expectations, emotionalisation, and appeals to authority - with speech act theory, which conceptualises open letters as performative acts that perform a particular stance while aiming to inform address and the public. The analysis identifies four recurrent strategies: (1) employing analytical terms to mobilise urgency and moral affect; (2) strong performatives that enact condemnation and solidarity; (3) appeals to scholarly authority structured by an exception-by-urgency logic; and (4) confessional speech acts through which letters perform self- and group-formation. The article argues that this confessional-performative structure produces two problems: many letters lack defined addressees, weakening their appeal function, and genocide/complicity framings often shift attention from actions to presumed intentions, reinforcing the friend-enemy polarisation characteristic of war discourse. As a result, the genre's reliance on moralised urgency and identity performance can undercut analytic deliberation and strain academic debate.