The article studies, from the concept of necessity developed by international law, the developing debate of the state of economic necessity and the way it operates as a circumstance precluding wrongfulness in the doctrine of Responsibility of States for Internationally Wrongful Acts. The article analyses the developments on the topic in the ICSID. The study aims to contribute in the debate on the effectiveness of circumstances precluding wrongfulness in the presence of the State’s financial commitments and tries to make a contribution to the understanding of “necessity”. The article intents to identify the legal effects when invoking the doctrine of necessity, such as the burden of proof of the necessity, the identification of a essential interest of the State that is affected, its effects on the calculation of damages and the annulment of certain awards by the misapplication of such doctrine. Key words: International Centre for Settlement of Investment Disputes, state of necessity in international law, responsibility of states for internationally wrongful acts, circumstances precluding wrongfulness, bilateral investment treaties.