Who of the following has propounded the theory of “Pacta sunt servanda” to explain the basis of…

The Italian jurist Dionisio Anzilotti explained the binding force of international law through the principle pacta sunt servanda: agreements between States must be kept. For him this was an absolute, ultimate norm from which the obligation of international law follows.

Kelsen placed the basic norm of international law in custom, Oppenheim based international law on the common consent of States, and Starke is known for his textbook rather than for this theory.