International Law: Sources, Treaties, Responsibility, and the Use of Force
What this domain tests
The 국제법 paper tests rule recall plus application to a short fact pattern: identify the source, state the rule, apply it, conclude.
Core rules
- Sources (ICJ Statute art. 38): treaties, custom, general principles; judicial decisions and writings are subsidiary. Art. 38 is a list, not a practical hierarchy.
- Custom: general practice - extensive, virtually uniform, including specially affected states (North Sea Continental Shelf) - plus opinio juris (Nicaragua). A persistent objector escapes a new rule.
- Jus cogens: peremptory norms (aggression, genocide, torture, slavery); a conflicting treaty is void (VCLT art. 53); erga omnes obligations are owed to all states (Barcelona Traction).
- Treaties (VCLT): pacta sunt servanda (26); interpretation by ordinary meaning, context, object and purpose (31); reservations barred if prohibited or incompatible with object and purpose (19); rebus sic stantibus read narrowly (62); signature creates a duty not to defeat object and purpose (18).
- Use of force: art. 2(4) prohibition; art. 51 self-defence, individual or collective, until the Security Council acts; anticipatory versus preemptive debate; R2P is not a freestanding legal basis.
- Immunity: restrictive sovereign immunity; VCDR 1961 inviolability and criminal immunity, waivable only by the sending state; persona non grata.
- UNCLOS: territorial sea 12 nm with innocent passage, contiguous zone 24 nm, EEZ 200 nm with sovereign rights over resources only.
Worked example
State A declares a 250 nm exclusive fishing zone. UNCLOS grants resource rights to 200 nm; beyond that lie the high seas, where fishing freedom applies subject to conservation duties. The claim is invalid beyond 200 nm.
Traps that cost marks
- Asserting a treaty binds a non-party because the rule is "customary" without proving practice and opinio juris.
- Confusing EEZ resource rights with territorial sovereignty.
- Citing art. 51 to justify humanitarian intervention.