Social media is increasingly used as a means of communication between states. Diplomats and political leaders are ever more relying on Twitter in their daily practice to communicate with their counterparts. These exchanges occur in view of a global audience, providing an added level of scrutiny that is unique to this form of communication. Twitter arguably challenges traditional notions of diplomacy according to which it is conducted through formal channels of communication and informal face-to-face social engagement. Yet we must ask how instrumental social media is as a tool for signalling intentions, and whether this medium can be an effective platform for dialogue and trust development when traditional face-to-face diplomacy is limited. Social media posts by state representatives reflect and frame state identity and how a state wishes to be recognized by others. If we are attuned to these dynamics, shifts in representational patterns communicated through social media during high-level negotiations allow realizations of political possibilities for change. Key here is the surprising nuclear deal between Iran and the P5+1 that analysts and policy-makers have struggled to explain. I argue that the role of Twitter as a key part of negotiation strategy is a crucial demonstration of how social media can shape the struggle for recognition, and thereby legitimize political possibilities for change. Understanding the increasingly prominent and powerful, yet largely unknown, variable of social media as a tool of diplomatic practice provides insight into the recurrent question of how diplomats affect change beyond upholding the status quo in the international order.