A+ Questions And Answers 2025/2026

Jus cogens norms constitute a special class of general rules made by custom. They have been endowed
with a special legal force, i.e. they are peremptory norms so that they may not be derogated from by
treaty or by ordinary customary rules. They have a rank and status superior to those of all the other
rules of the international community.
A treaty contrary to a jus cogens norm is null and void ab initio.Jus cogens norms can also have effect on
making reservations: inconsistency with a peremptory norm makes a reservation inadmissible.
2
Students need to explain the concept of fragmentation of international law and thereafter clarify its
meaning in the context of proliferation of courts and tribunals.
E.g. International law has been developed in a fragmented manner for certain policy areas as problems
were identified. This development entails that international law has developed to address certain
problems, or in a functional manner. Examples of relevant areas of law are human rights law, the law on
the use of force, humanitarian law, international trade law, international environmental law,
international economic law and the law of the sea. The distinct bodies of law that emerged as a result of
the development of functional areas of law, in response to identified problems, not only provide
substantive rules of law but also led to the establishment of international courts and tribunals with
competences to decide cases within a distinct body of law.
A problem which arises in the context of the proliferation of courts is that a case or related cases may be
brought before different courts or tribunals, which may come to different decisions as to which of the
parties violated international law or to different interpretations of the law, thereby contributing to the
fragmentation of international law.
Additionally, students need to exemplify their answer with at least one concrete example. See e.g. ICJ
Nicaragua case vs ICTY Tadic case; Swordfish case, Mox plant cases and the cases as discussed in the
seminar on proliferation.
3
The answer is to be found in Article 36 (paras. 1 & 2) ICJ Statute. The following states can be parties to a
dispute: States Members of the United Nations and other States which have become parties to the
Statute of the Court or which have accepted its jurisdiction under certain conditions. The Court is
competent to entertain a dispute only if the States concerned have accepted its jurisdiction.