abstract. The Holy See has bilateral treaties with sixty-four countries across the globe. These international legal documents, or concordats, are not mere diplomatic formalities but hard-won negotiated settlements between Church and state. Focusing on Italy, Poland, and Malta, this Note argues that the concordats often integrate Church doctrine and canon law into the domestic legal systems of signatory states, particularly in the areas of antidiscrimination law, marriage, and education. In so doing, this vast treaty regime subordinates LGBTQ people as a matter of law. Ultimately, I show that the Church today is not just a bottom-up force influencing moral and social attitudes toward queer people but also a top-down architect of international law.

The Note theorizes and evaluates the various avenues available to advocates and signatory states aiming to challenge the Church’s treaties. Interpretation, litigation, withdrawal and renegotiation, and countermeasures are all viable methods of contesting the concordatarian structure. However, advocates and states must be cautious not to place too much pressure on the bedrock principle of international law: pacta sunt servanda, agreements must be honored. Activists and states can and should reform the Church’s treaty regime to make room for full LGBTQ equality, but they should ensure that in doing so, they preserve the norms undergirding the international legal order.

author. J.D. expected 2026, Yale Law School; B.A. 2022, Yale College. All views expressed in this Note are my own. Yet I am deeply indebted to Professor Oona A. Hathaway for teaching me the intellectual building blocks I needed to write this Note, from countermeasures to the basics of what a treaty is. Without her feedback and encouragement throughout the process, this Note would have never materialized. I also owe a debt of gratitude to Professors Paul Gewirtz, Abbe R. Gluck, Reva B. Siegel, and Emma Sokoloff-Rubin for teaching me to have faith in my own ideas during my first year of law school. I am grateful to the students in Professor Hathaway’s “International Law” class who provided me feedback on my early drafts: Thomas Poston, Krister Rasmussen, Zachary Brown, and Tilly Brooks. I am thankful for the guidance and support of Yale Law School’s fantastic international legal librarians, Lucie Olejnikova and Steven Mitchell. And, of course, I extend a huge thank you to the Yale Law Journal editors who sourcecited, edited, proofed, and substantially improved my Note, especially Fiona Furnari, whose careful and extensive edits challenged me to scrutinize and strengthen my ideas. I also thank Shreya Minama Reddy, Beatrice L. Brown, Deja R. Morehead, and Lily Moore-Eissenberg. Last but not least, I thank my mother, Professor Marjorie Lehman, for teaching me the power of religion as a force for good—in law and in life. All errors are, regrettably, mine alone.

Introduction

In November 2020, the lower house of the Italian Parliament approved a landmark bill protecting LGBTQ people from violence and hate speech.1 When the so-called “Zan bill” reached the Senate, the Catholic Church2 expressed its formal diplomatic opposition through a letter called a note verbale.3The Holy See, the Catholic Church’s governing body, argued that the bill would violate its treaties with Italy, the Lateran Pacts of 1929, by limiting Italian Catholic freedom.4 By October 2021, the Zan bill was dead.5

This Note aims to unearth the role of concordats—the Church’s international treaties—in obstructing the advancement of LGBTQ rights in contemporary Europe. Contrary to the traditional scholarly view,6 concordats are not mere formalities establishing diplomatic relations between the Holy See and friendly countries. Instead, they are often instruments of Church power that integrate Church doctrine into state legal systems and subordinate LGBTQ people as a matter of law. Concordats have embedded Church influence and canon law7 into domestic legal domains like antidiscrimination law, marriage, and education, so that states must, for example, teach only Church-approved texts or provide Church marriages with civil legal effect.8 After uncovering the influence of concordats, this Note outlines how states and LGBTQ activists alike can confront and contest the concordatarian system. It does so by analyzing three case studies: Italy, Poland, and Malta. These three countries make for an instructive contrast. Despite their similarity on paper—they are all Catholic-majority European states9—Italy, Poland, and Malta have had very different fates under the concordatarian regime. In just the last nine years, Malta has become the most progressive country on LGBTQ issues in Europe, while Italy and Poland lag distantly behind.10

This Note aims to demonstrate that the modern Church is not only a bottom-up arbiter of social and cultural power but also a top-down creator of international law in its own image. Scholars have long studied how the Church helped build the modern architecture of international law.11 A nineteenth-century scholar described the historical role of the Pope as an “independent international magistrate, head of the supreme tribunal for the settlement of international disputes.”12 But the ways in which the Church today continues to enact and enforce international law remain woefully understudied.13 While the first concordat was signed in Worms in 1122,14 the Church has concluded more treaties in the last sixty years than it has in its entire history. As of the writing of this Note, the Church has formed 195 treaties since the Second Vatican Council in the 1960s—eighty-one of which were concluded since 2001.15 Concordats, then, are not a relic of history.

This Note proceeds in three Parts. Part I uses the history of the modern concordats in Italy, Poland, and Malta to illustrate how these treaties emerged amid sharp contestation between the Holy See and the state. These countries’ concordats are not the products of polite correspondences between diplomats. Rather, they are hard-won, negotiated settlements resulting from battles—sometimes violent ones—between Church and state. Ultimately, this Part demonstrates how the Church exacted major concessions from its state partners and, after decades of struggle, made sure to get those promises in ink.

Part II examines the contemporary entrenchment of Church doctrine in the domestic law of Italy, Poland, and Malta. If concordats are negotiated settlements in which the Church fights for civic space, this Part shows the consequences of the Church’s victories for LGBTQ people today. Divided into three Sections covering antidiscrimination law, marriage, and education, this Part provides insight into why concordatarian states can have such divergent pathways.

Part III explores ways to challenge and circumvent the existing concordatarian regime. Over four Sections—covering interpretation, litigation, withdrawal and renegotiation, and countermeasures—this Part delineates increasingly powerful actions available to individuals and states under international law. This structure serves two goals. It recognizes that, as delicate peace agreements, concordats demand caution from their challengers, who should adopt more drastic measures only as less severe interventions fail. Second, the sliding scale of Part III captures the importance of retaining the fundamental principle of international law, pacta sunt servanda—agreements must be honored—as the normative baseline in all efforts to confront the concordats. Each measure examined in Part III places greater strain on the principle. And while some degree of strain is necessary for legal reform, too much pressure can bend the rule too far.