State Engagement with Treaties

Abstract

This chapter explores the interaction between domestic and international law in relation to the state’s engagement with treaties. Treaty engagements are important mechanisms through which states conduct their foreign relations. The domestic allocation of responsibility for the making and unmaking of treaties is therefore a significant question of the constitutional separation of powers in the realm of foreign relations law. Treaties are also international legal instruments, facilitating the development of international law and international institutions. The domestic and international law of treaties therefore both concurrently regulate the state’s power to join and leave treaties. This chapter examines the relationship between these two bodies of law in this regard, setting out developments in domestic jurisdictions establishing constitutional limits on the executive’s power to enter and exit treaties, and addresses the possible impact of these constitutional developments in the international law of treaties.