Despite longstanding attention to rhetorical form and structuring logics that give discourse its persuasive power (metaphor, genre, narrative, definitional frames, ideology, etc.), the relative amount of publication attending to international rhetoric remains slight. As the composition of audience(s) has stretched to global proportions the challenges of apprehending the manifold cross-cultural complexities for presidential address have expanded. Spanning five decades and three presidencies (Kennedy, H.W. Bush and Clinton), this dissertation takes presidential public address at the United Nations as its object of study in an effort to help remedy this shortcoming, while also aiming to provide a richer theoretical underpinning for accounts of globalization and its impact on the modern presidency. The analysis grapples with three particular problems: conceptualizing increasingly pluralized audiences, the matter of ascertaining how non-American institutions (like the United Nations) shape and are shaped by American rhetorical productions, and the difficulties in gauging presidential rhetorical efficacy. Two main arguments are advanced. First, the dissertation argues that presidential rhetoric at the United Nations traffics in a particular brand of cosmopolitanism, which helps presidents to constitute a universal audience nonetheless ideologically sympathetic to American goals. The terrain and implications of this cosmopolitanism rhetoric are mapped and unpacked. Second, it is argued that when crafting rhetoric for the specific audience of the United Nations General Assembly, the President is obligated to work within the confines of the rhetorical institution that is the United Nations. The project seeks to understand the limits and possibilities of presidential rhetoric based on existing international institutional constraints. Taken together, the resulting scene of presidential cosmopolitan address, rather than culminating in efforts primarily concentrated on persuasion, end up mainly interpellating a global audience supportive of a cosmopolitan agenda which in turn is pre-structured to support the interests of the United States.