(2) Sources of Public International Law

• What is the more commonly used term for conventions in public international law?

  Treaties
• How did the Law of Treaties evolve?

  Through customary law, codified in VCLT
• What does Article 2(1)(a) of the VCLT define?

  A Treaty as an international agreement
• When do the provisions of the VCLT not apply to a Treaty?

  When one party is not a State
• What is the oldest source of international law?

  International Customs
• What is the material element of custom in international law?

  General practice of States that is widespread
• What is Opinio Juris in the context of international customs?

  The belief that a practice is legally binding
• What are the three elements needed to establish a custom?

  Practice duration, generality, and consistency
• How quickly can a custom emerge according to the North Sea Continental Shelf case?

  Quickly if the majority of States follow a practice
• What does Article 38(1)(b) refer to in terms of custom?

  General practice of States
• What is required for a practice to be considered a custom?

  It must be generally followed by States
• What is the difference between universal and local customs?

  Universal customs bind all States; local customs bind only some
• What did the court find in the Asylum Case regarding consistency in custom?

  There was too much uncertainty to establish custom
• What did the Military and Paramilitary Activities Case (1986) state about consistency?

  General consistency is required, not absolute conformity
• What does Opinio Juris convert a practice into?

  Custom
• What is a rule of jus cogens?

  A rule from which no derogation is permitted
• Do international court decisions make law?

  No, they serve as evidence of State practice
• Who are ICJ decisions binding on?

  Only the parties involved
• What are the key elements of international customs?

  • Material element: General practice of States
  • Opinio Juris: Psychological belief in legal obligation
  • Duration: Time-related aspect of practice
  • Generality: Widespread adherence by States
  • Consistency: Uniformity in State actions
• What distinguishes jus cogens norms from other international laws?

  • Superior to all other international laws
  • No derogation permitted
  • Can only be modified by similar norms
• What is the role of the International Court of Justice (ICJ) in international law?

  • Provides advisory opinions
  • Resolves disputes between States
  • Evidence of State practice, not law-making