https://doi.org/10.1177/0047117820965656 International Relations 2022, Vol. 36(1) 40–60 © The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0047117820965656 journals.sagepub.com/home/ire Personality and adherence to international agreements: The case of President Donald Trump Scott Fitzsimmons University of Limerick Abstract Although Donald Trump’s foreign policy behavior is often characterized as erratic and unpredictable, he was remarkably consistent in his hostility toward international agreements. The president withdrew or threatened to withdraw the United States from several agreements and consistently characterized agreements as ‘horrible deals’ that ‘cheat’ his country. This article explores why Trump exhibited such consistent disdain for international agreements. To address this question, it develops propositions that draw a causal link between a leader’s personality traits and their willingness to challenge constraints: a leader with a relatively high belief in their ability to control events is more likely to challenge constraints than a leader with a lower belief in their ability to control events; moreover, a leader with a relatively high level of distrust of others is more likely to challenge constraints than a leader with a lower level of distrust of others. The article then conducts a plausibility test of these propositions in the context of Trump’s decisions to withdraw from agreements in three significant policy areas: trade (the Trans-Pacific Partnership), environmental stewardship (the Paris Agreement on climate change), and nuclear proliferation (the Iran nuclear deal). Keywords Donald Trump, foreign policy, international agreements, leadership traits, personality At the time of writing of this article, the liberal international order was under assault from within by its chief architect, the United States (U.S.) or, more specifically, its then president, Donald Trump. 1 A central pillar of this eight-decade-old order is made up of agreements that bind countries together through a mutual pledge to abide by rules regulating a range of Corresponding author: Scott Fitzsimmons, Department of Politics & Public Administration, F1022 – University of Limerick, Limerick, Ireland. Email: scott.fitzsimmons@ul.ie 965656IRE 0 0 10.1177/0047117820965656International RelationsFitzsimmons research-article 2020 Article