Over the last decade, the United States (US) and European Union (EU) have clashed over whether personal data can be transferred internationally between their jurisdictions. Scholars have largely attributed this disagreement to structural factors such as economic interdependence and different social understandings of privacy. In this thesis, I argue that the extant literature too heavily emphasizes structural explanations and overlooks how actors have strategically constructed the legal norms that govern transatlantic data flows. While I acknowledge that structural factors explain much about this disagreement, I maintain that the recent instability cannot be fully understood without carefully examining the strategies actors have employed to influence this governance. I examine these strategies through the method of discourse analysis. I collated many documents (n = 51) where actors attempted to speak persuasively about transatlantic data flows and then used these documents to analyze how data flows were rhetorically framed. I found meaningful variation in the framing strategies employed by different types of actors and the persuasive effects these frames have had. These findings show that, within the parameters of structure, actors in the US and EU have exercised their agency to defend and contest legal norms from the bottom up. I conclude by recommending policies that would foster greater agreement and stability in the governance of transatlantic data flows.