Competing Sovereignty and Laws’ Domains

We live in a world of multiple sovereignties. Many think of nation-states as the principal sovereign actors, but sovereign substates and international institutions created by states also hold sway. Each claims a domain, an area (spatial, temporal, conceptual) over which it rules. Ruling includes adopting and applying law.

When domains overlap, laws can clash. Competition among sovereigns over legal domains poses a challenge to people who take law into account as they live their lives and plan their futures. What makes these issues immediately important is the growth of the international-law enterprise over the last quarter-century. Both the ambitions and the institutions of international law expanded greatly in the decade after the collapse of the Soviet system.

Even though it currently faces assaults from nationalist populists in the rich world and elsewhere, international law remains important and even indispensable. Its influence means more frequent and more intrusive claims about its domain to the derogation of national and subnational law. Such domain conflicts always existed, but they have grown in salience. This Article argues that domain assignments based on the rational interest of sovereigns produce a defensible world in which to live.

Rational-interest assignments based on adherence to formal rules provide the best response to the important questions: Why not give greater normative content to assignment rules? When should sovereigns forego the benefits of cooperation to defend particular interests? Are all normative preferences local (particular to the sovereign in question), or are there universal preferences that should or must override domain conflicts? These questions are significant because domain assignment, however necessary for law to function, represents a specialized legal practice that receives little popular attention.

Defending the use of systemic rules when they clash with a particular sovereign’s normative preferences thus becomes an exercise in justifying law as something other than expression of normative values. At bottom, the question is whether a satisfactory conception of the rule of law can embrace formal constraints that may override normative commitments to values such as human dignity and the squashing of arbitrary discrimination.