The Significance of State Consent

States' international legal obligations are largely based on their consent, most explicitly in the form of treaties that include international dispute settlement. The conditions, limitations and incompleteness of such consent has led to renewed attention to the question of why and when state consent should matter for international legal obligations, and hence for the international courts and tribunals (ICs). The paper provides an overview of some of the most salient theoretical puzzles an improved account should address, including - the normative significance of consent by undemocratic states; - the normative grounds for non-consent based sources of international law such as international customary law, jus cogens - the normative role of explicit non-consent, including in the 'persistent objector' doctrine, non-acceptance of normatively obligatory treaties, and the exit from treaties - the appropriate role of non-consent based sources when ICs interpret and adjudicate