Rules and norms derive from their sources. The sources articulate what the law is and where it can be found. The sources of international law can be found in article 38 of the Statute of the International Court of Justice. Article 38 of the Statute of the ICJ states: ‘The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply: a. international conventions, whether general or particular, establishing rules expressly recognized by the contesting states; b. international custom, as evidence of a general practice accepted as law; c. the general principles of law recognized by civilized nations; d. subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.’ A rule must derive from one of these sources in order to be considered international law.’
Custom in international law is a practice followed by those concerned because they feel legally obliged to behave in such a way. Custom must be distinguished from mere usage, such as behavior which may be done out of courtesy, friendship or convenience rather than out of legal obligation or a feeling that non-compliance would produce legal consequences, for example sanctions imposed by other members of the international community. This is also a requirement for opinion juris. The source judicial decisions and scholarly writings are subsidiary means for the determination of the law. Both municipal and international judicial decisions can serve to establish new principles and rules. In municipal cases, international legal rules can become clear through their consistent application by the courts of a number of states. In the Nicaragua Case the Treaties, Conventions, general principles and customary law are used as sources of law. As are General Assembly resolutions which derive from the source writings.
The judges in the Nicaragua Case relied on many treaties while forming their judgment. They relied on the following treaties: * The 1956 treaty : Treaty of Friendship, Commerce and Navigation of 1956 * The Hague Convention No. VIII of 1907
* Four Geneva Conventions of 12 August 1949
* Article 8 of The Convention on Rights and Duties of States * Article 1 of the Convention concerning the Duties and Rights of States in the Event of Civil Strife * Article 18, 20 and 21 of the OAS Charter
* Article 51, article 2(4) of the UN Charter,
* Resolution 2625 (XXV) "Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in Accordance with the Charter of the United Nations" * General Assembly resolution 3314 (XXIX)
As said before the judges also relied on international customary as a source. A rule of customary international law identified in the case would be the principle of non-intervention. The Principle of nonintervention as used in International law refers to a rule that a country should not interfere in the internal affairs of another country. The rule is based upon the principles of state sovereignty and self-determination. This principle is also embodied in Article 2(7) of the U.N. Charter which binds it from intervening “in matters which are essentially within the domestic jurisdiction of any state.” The judgest in the case state that ‘It therefore finds that the support given by the United States to the military and paramilitary activities of the contras in Nicaragua, by financial support, training, supply of weapons, intelligence and logistic support, constitutes a clear breach of the principle of non-intervention.’
The judicial decisions which find their legal grounds in article 38 of the UNC are part of case law. Case law is the decisions, interpretations made by judges while deciding on the legal issues before them which are considered as the...