1. Hierarchies and relationships between norms

2. Nicaragua Case
The 1946 US Declaration conferred jurisdiction on the ICJ, but excluded:
”disputes arising under a multilateral treaty, unless (1) all parties to the treaty affected by the decision are also parties to the case before the Court, or (2) the United States of America specifically agrees to jurisdiction”
US Government argued:
”the provisions of the UN Charter … subsume and supervene related principles of customary international law”
ICJ:
Rules are nor necessarily identical
Even if they were, they derive from separate sources of law (§§ 177 ff.)

3. Art. 53 of the VCLT
A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law. A peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.”
Jus cogens as lex superior
Who is bound by the characterisation of a norm as jus cogens?
What other kinds of conflict involving jus cogens can be envisaged?

4. Bosnia Genocide, Sep. Op. Judge Lauterpacht
Why should the resolution adopted by the UNSC not be acted upon?
Jus cogens serves to limit the powers of the SC
Lex superior prevails over lex inferior
The resolution is in conflcit with jus cogens and therefore void

5. Art. 103 of the Charter of the UN
”In the event of a conflict between the obligations of the Members of the United Nations under the present Charter and their obligations under any other international agreement, their obligations under the present Charter shall prevail.”

6. Art. 53 of the VCLT
”A peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.”
Who makes jus cogens norms?

7. Jurisdictional Immunities of the State
Italy allowed tort claims to be brought against Germany originating in war crimes and crimes of humanity committed by German armed force in
Germany:
Italy had failed to respect the jurisdictional immunity of Germany under customary international law
Italy:
Germany was not entitled to immunity because acts committed involved violations of jus cogens
ICJ:
“The two sets of rules address different matters.” (para. 93)

8. Art. 53 of the VCLT
“A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law.”
What is the concept of conflict assumed?

9. Aerial Observation flights over Åland Islands
1921 Convention Respecting the Non-fortification and Neutralisation of the Åland Islands; Art. 2:
”[N]o military, naval or air force of any Power shall enter or remain in the zone”
1992 OSCE Open Skies Agreement
According to its preamble, the Treaty promotes ”openness and transparency”; it facilitates ”the monitoring of compliance with existing or future arms control agreements”
Means to reconciliate obligations

10. “Some international norms have a constitutional law character”
Suggestions include:
The law of the UN Charter
The jus ad bellum
Rules of jus cogens
If the characterisation is appropriate, then why?