Managing global migration is one of the most pressing issues of our time. Traditionally, international law has not generally regulated immigration and citizenship law; it defers to state authority in setting up rules and procedures for entry into the territory and citizenry. The lack of clear regulation—and a commonly accepted methodology on how to evaluate discriminatory borders—creates acute problems in terms of protecting human rights, promoting state interests, and setting up international cooperation. Against this background, this essay offers a legal framework to examine when borders are discriminatory. It includes a three-step process that examines the goals, criteria, and means of immigration and citizenship selection. With almost 300 million international immigrants worldwide living outside their country of origin in 2020, developing such a framework has become an urgent need.

Global migration yields political shifts of historical significance, profoundly shaking up world politics as manifested by the European refugee crisis, the Brexit referendum, and throughout the US election. The refugee crisis—which, from a human rights perspective, is first and foremost a crisis of protection—has enhanced the already-existing discussion on justifiable and unjustifiable attempts by nation-states to safeguard their constitutional “essentials” by reinforcing border controls and using selective immigration and citizenship policies. How can liberal states, or a supranational Union formed by such states, welcome immigrants and treat refugees as future denizens without fundamentally changing their constitutional identity, forsaking their liberal tradition, or slipping into populist nationalism? This question is one of the greatest contemporary challenges in constitutional law and theory nowadays.

The Article examines the wisdom of loyalty oaths as a legal institution in contemporary liberal democracies. First, using comparative analysis the Article highlights the growing global interest in loyalty oaths. Second, based upon historical evidence the Article explores the functions of loyalty oaths and assesses their role. Third, through using legal analysis the Article challenges the validity of loyalty oaths and identifies three fundamental problems related to their content and form: the rule of law, freedom of conscience, and equality.The Article reveals liberal concerns associated with the added value of the duty of “loyalty to the law” (allegiance), as distinct from the duty to “obey the law” (obedience). It presents an ongoing tension between loyalty and liberalism and argues that the more loyalty liberal democracies demand, the less liberal they become. The Article concludes that loyalty oaths yield high costs but have low benefits and suggests that liberal states should abandon them as a legal institution.