International Case law

North Sea Continental Shelf

Established the requirements of customary law. Requirement of state practice (usus) and opinio iuris where state render it obligatory.

Nicaragua case

There is no requirement for rigorous conformity with a customary law however it should be generally consistent with it inconsistent activity will be treated as a breach and not as the formation of a new custom.

Nuclear tests case

States can show their intent to be bound by a legal obligation though unilateral statements which are binding

Palmas case

Established that continuous and peaceful display of territorial sovereignty (effective occupation) is superior to mere discovery or geographic contiguity.

Lotus case

Rules of international law binding upon States emanate from their own free will and consent

Tehran Hostages case

A state becomes liable for the actions of other groups by supporting them and adopting their actions as their own effectively making them an organ.

Arrest Warrants case

Heads of states can be prosecuted under five conditions:

• By their national courts

• Their own state waives immunity

• After their term ends

• By international courts

NIC case

A state is liable for acts of insurrectionist groups which violated international law provided that the state had effective control over the operations in which the alleged violations took place.

ICJ Genocide case

For violations of human rights law it must be shown that the state had effective control over the militia in respect to each operation in which violations were committed.

Jurisdictional immunities of the state

There is no exception in customary international law that deprives a state of immunity simply because it is accused of serious violations of international law, including war crimes.

ICJ Reparations case

International organizations have rights, duties, and can bring claims under international law to the extent necessary to carry out its functions.

Nuclear weapons case

Three requirements for specialized agencies to request an advisory opinion from the ICJ:

1. The organisation must be duly organised

a. Meaning whether it is an IGO

2. The question must be a legal question

3. The question must address a matter that arises within the ‘scope of activities’ of the organisation