One of the most important discussions in international law is the bound of states to obligations which have been accepted with consent. The acceptance of international treaties is based on sovereignty equality of state and their independence at the domain of international relations.The theory that the basis upon which an international legal norm is binding is the consent of states. The consensual theory holds that a state is not bound by a legal norm to which it has not given its express consent. Conversely, should a state not clearly and openly object to a particular norm, then it can he considered to have given its tacit or implied consent to that norm (e.g. custom and usage).The consensual theory has a long tradition, as it formed the basis of the historical Western international legal order begun through custom and usage based upon the consent of states. In the modem world of ideological conflict and. World states, the consensual theory of international law remains appealing to many states because it reinforces their sovereignty and independence of action. Rather than being bound to existing international legal norms by virtue of being accepted into the community of nations, states claim that the need for their consent allows them selectively to bind themselves to specific norms rather than the inclusive body of extant law.At the same time, the consensual theory undermines the predictability and regulatory utility of law by its selective application. The theory also clashes with the concept of jus cogens (peremptory norms which bind all states) and Erga omnes obligations.Whilst the foregoing is concerned with the obligation owed by one state to another, contemporary international law also recognizes the concept of Erga omnes that is, obligations owed by every state to the international community as a whole. These obligations were identified by the International Court of Justice in the Barcelona Traction Case as deriving from “the outlawing of acts of aggression, and of genocide” and from “rules concerning the basic rights of the human person, including protection from slavery and racial discrimination.” Thus, by their nature, such obligations are the concern of all states and, because of the importance of the rights involved, all states have a legal interest in their protection.Certain consequences following from the basic concepts of peremptory norms of general international law and obligations to the international community states as a whole within the field of State responsibility.