This study provides a critical-pragmatic analysis of fallacious argumentation in the February 28, 2025 Oval Office discourse between U.S. President Donald Trump, Vice President J.D. Vance, and Ukrainian President Volodymyr Zelenskyy. The encounter reveals how fallacies function not merely as reasoning flaws, but as strategic linguistic tools for discursive domination. Drawing on Walton’s pragmatic theory of fallacy, the pragma-dialectical model, and CDA, the research examines how ad hominem attacks, straw man arguments, false dilemmas, and appeals to emotion are employed to assert control, constrain responses, and construct ideological binaries. The study adopts a qualitative-critical approach. It analyzes a transcribed ten-minute segment of the meeting using speech act theory, Gricean implicature, and CDA principles. The findings demonstrate that Trump and Vance deploy fallacious reasoning to construct conversational contexts and coerce Zelenskyy into performative compliance. In contrast, Zelenskyy uses hedging, politeness, and discursive mitigation as resistance strategies to preserve face and diplomatic balance. The analysis shows that fallacies are not rhetorical coincidences, by-products, or incidental occurrences but deliberate speech acts embedded in broader claims to communicative authority, legitimacy, and symbolic power. As such, this study contributes to political linguistics and argumentation theory by illustrating how critical pragmatics can reveal the ideological functions of language in power-imbalanced political dialogues.