States — Federal States and Confederations — Application of international law in dispute between States within Federation — Treaty dispute between Länder of Federal Republic of Germany

States — Conduct of foreign relations — Treaty-making powers — Role of executive — Role of legislature — Discretionary powers of executive — Whether denunciation requiring ratification by legislature

Treaties — Termination — Denunciation — Multilateral treaties — Effects of denunciation — Treaty providing for denunciation without determining its effects — Whether denunciation resulting in withdrawal of denouncing party or dissolution of treaty relationship — Lack of general rule under customary international law — Whether dissolution or withdrawal more closely corresponding to hypothetical intention and interests of the parties

Treaties — Termination — Legal validity — Denunciation — Whether requiring ratification by legislature — Counter-denunciation — Conditions for effectiveness — Principle of good faith — Whether residual obligations are created by withdrawal from multilateral treaty relationship by one of the parties

Treaties — Interpretation — Rules of interpretation — Vienna Convention on the Law of Treaties, 1969, Articles 31 and 32 — Intention of parties — Supplementary means of interpretation — Preparatory work — Circumstances of conclusion — Object and purpose of treaty — Subsequent practice of parties — Application of rules of international law to dispute concerning gap in provisions of treaty between Länder of the Federal Republic of Germany

Sources of international law — General principles of law — Loss of rights — Mistake in interpretation of treaty — Estoppel — Acquiescence

International organizations — Legal status — Common institutions established by multilateral treaty — Effect on operation of institutions of withdrawal of one of the parties to treaty — Norddeutscher Rundfunk — The law of the Federal Republic of Germany