Customary international law (2) / relationship between customary international law and treaty law / general principles of law (1) S5

Question 1

Name and explain exceptions on customary international law

Answer 1

Exceptions on customary international law:
1) Persistent objector: a State that consistently rejects a new custom from the start is not bound by it

2) Jus cogens norms: fundamental rules (e.g., prohibitions on slavery, genocide, torture) that no State can opt out of

Question 2

Name and explain the relationship between customary international law and treaty law with regarding to overlap in rules

Answer 2

Relationship between customary international law and treaty law with regarding to overlap in rules:
1) When a treaty reflects existing customary international law, signatory states are bound by both

2) Non-signatory states are only bound by customary international law

Question 3

Explain what is confirmed in the Nicaragua case

Answer 3

Nicaragua case: the ICJ confirmed that all states may follow the same rules if those rules are customary international law, regardless of treaty participation

Question 4

Explain what is confirmed in the Wall case

Answer 4

Wall case: the ICJ confirmed that treaties can contribute to the development of new customary international law if widely followed

Question 5

Name and explain the rules about legal priority if a treaty and customary international law conflict

Answer 5

Legal priority if a treaty and customary international law conflict:
1) Jus cogens norms always take priority

2) Treaties usually prevail between signatories

3) New custom may override older treaties (lex posterior)

4) More specific rule prevails over general rule (lex specialis)

Question 6

Name and explain the mutual support between customary international law and treaty law

Answer 6

When customary international law and treaty law aligned, they reinforce each other and enhance legal certainty

Question 7

Defenition general principles of law?

Answer 7

General principles of law: legal rules common to many national legal systems and widely accepted as part of international law

Question 8

Explain the purpose of general principles of law

Answer 8

Purpose of general principles of law: they serve as gap fillers, used when no treaty law or customary international law applies

Question 9

Name examples of general principles of law

Answer 9

Examples general principles of law
1) Pacta sunt servanda (agreements must be kept)

2) Good faith

3) Estoppel

4) Liability for damages

5) Equity

Question 10

Explain how courts general principles of law use

Answer 10

Courts rarely use general principles of law by the International Court of Justice (ICJ) but often influence legal reasoning