international law 2

pacta sunt servanta

“agreements must be kept”; codified in Article 26 VCLT; treaties in force are binding and must be performed in good faith.

good faith

obligations must be sincerely performed (at every stage) without abuse of rights or exploitation of loopholes

Vienna Convention on the Law of Treaties (VCLT)

adopted in 1969 and in force since 1980; governs the entire lifecycle of a treaty; reflects customary international law and thus binding on non-parties

Treaty (VCLT definition)

an international agreement concluded between states in written form, governed by international law, whatever its particular designation

substance over form principle

the name of an instrument doesn’t determine its legal status; what matters is party intention, language used, and their conduct

Philip Allott

described treaties as “disagreement reduced to writing”; international law structures but does not eliminate political conflict

Full powers (Article 7 VCLT)

formal document granting authority to negotiate/sign treaties; required for all representatives except Heads of State, Heads of Government, and Foreign Ministers, who have automatic authority

Automatic authority

the three officials who can bind a State without producing credentials: Head of State, Head of Government, Foreign Minister

Authentication

the step fixing the treaty text as definitive and authentic; done by initialling, signing, or signing the Final Act; does not create binding obligations

Signature

in simplified agreements: constitutes consent to be bound; in formal treaties: a preliminary step that authenticates the text but does not yet bind the State

Article 18 VCLT

obliges a State that has signed a treaty subject to ratification to refrain from acts that would defeat the object and purpose of the treaty before ratification; a negative obligation only, not required to act as if treaty is in force

Ratification

the act by which a State formally confirms consent to be bound; allows domestic approval processes to occur; the moment the treaty becomes binding on that State

Accession

joining a treaty after the fact, without having originally negotiated or signed it; same legal effect as ratification

Entry into force

when a treaty becomes binding on its parties; determined by the treaty's own terms, usually requiring a minimum number of ratifications

Registration (Article 102 UN Charter)

treaties must be registered with the UN Secretariat; consequence of non-registration: the treaty cannot be invoked before any UN organ including the ICJ; does not invalidate the treaty between the parties

Denunciation

the formal act of withdrawing from a treaty; must comply with the treaty's own withdrawal clause if one exists

Soft law

non-binding instruments (declarations, MoUs, guidelines) that deliberately sit outside the treaty framework; allows speed and flexibility; blurs the line between law and politics; increasingly common in environmental and regulatory cooperation

Reservation (definition)

a unilateral statement made when signing, ratifying, or acceding to a treaty, by which a State purports to exclude or modify the legal effect of certain provisions in their application to itself.

Universality vs. integrity tension

the core tension reservations manage: broad participation (universality) vs. ensuring the treaty means something (integrity); reservations are the pragmatic compromise.

Unanimity rule

the old rule requiring all existing parties to accept a reservation before the reserving State could join; abandoned after the Genocide Convention Advisory Opinion (1951) as unworkable for large multilateral treaties

Object and purpose test

the standard replacing the unanimity rule; a reservation is permissible if compatible with the object and purpose of the treaty; codified in Article 19(c) VCLT

Article 19 VCLT, three prohibited grounds for reservations

(1) treaty expressly prohibits the reservation

(2) treaty allows only specified reservations and this isn't one of them

(3) reservation is incompatible with the object and purpose of the treaty

Acceptance of a reservation

treaty applies between accepting State and reserving State with the reserved provision excluded or modified

Objection to a reservation

objecting State can either: treat the treaty as not in force between itself and the reserving State; or allow the treaty to apply between them with the reserved provision excluded

Bilateral relationship problem

reservations create a complex web of slightly different bilateral arrangements within a single multilateral treaty; it stops being a single uniform instrument

Human rights treaty problem

obligations in human rights treaties run to individuals, not other States; other States have no incentive to object to reservations because they're not directly harmed; no practical enforcer of the compatibility requirement

General Comment 24 (Human Rights Committee, 1994)

argued the Committee itself should assess reservation compatibility; incompatible reservations are severable and State is bound by the treaty without the reservation; controversial because it contradicts the State-consent model

Severability

the doctrine that an incompatible reservation can be stripped away, leaving the State bound by the full treaty as if the reservation was never made; deeply contested

Article 31 VCLT; general rule of interpretation

a treaty shall be interpreted in good faith in accordance with the ordinary meaning of its terms, in their context, and in light of its object and purpose; four elements operate simultaneously as a single integrated operation, not a hierarchy

Ordinary meaning

the plain meaning of words as understood by a reasonable person; the starting point of interpretation; raises question of meaning at time of drafting vs. today

Context (Article 31(2))

includes the text (preamble and annexes), agreements made between all parties in connection with conclusion, and instruments made by one or more parties and accepted by others as related to the treaty; must involve all parties, not just some

Object and purpose for interpretation

the teleological element; interpretation should serve what the treaty was designed to achieve; can create tension with ordinary meaning

Article 31(3) VCLT

three further elements that shall be taken into account: (a) subsequent agreements between all parties on interpretation; (b) subsequent practice in applying the treaty; (c) relevant rules of international law applicable between the parties (systemic integration)

Subsequent practice

the actual behaviour of parties in applying the treaty over time; if consistent and general, establishes the agreed interpretation; allows treaty meaning to evolve without formal amendment

Systemic integration (Article 31(3)(c))

treaties must be interpreted in light of other applicable rules of international law; treaties don't exist in isolation

Article 32 VCLT — supplementary means

recourse to travaux préparatoires and circumstances of conclusion; only permitted when Article 31 leaves meaning ambiguous or obscure, or produces a manifestly absurd or unreasonable result; secondary, not primary

Travaux préparatoires

preparatory works: negotiating history, draft texts, conference records, position papers; treated as secondary because they're often incomplete, contradictory, unavailable to later-joining States, and potentially manipulable

Article 33 VCLT — multiple languages

all authentic texts are equally authoritative; treaty presumed to have the same meaning in each; if divergence cannot be resolved by Articles 31–32, adopt the meaning that best reconciles the texts having regard to object and purpose

Contemporaneous interpretation

treaty terms mean what they meant at the time of drafting; respects original consent; can produce absurd results for long-standing treaties

Evolutionary interpretation

general terms evolve with changing circumstances and should be interpreted in light of current conditions; favoured by ICJ for generic terms; risk of judicial legislation with courts rewriting treaties under guise of interpretation

Generic vs. specific terms

evolutionary interpretation is more defensible for generic terms (commerce, investment, cruel treatment) intended to evolve; less defensible for specific terms with a clear fixed meaning at drafting

Textual school of interpretation

prioritises ordinary meaning; text is best evidence of what was agreed; weakness: words are inherently ambiguous, ignores deliberately vague drafting

Intentionalist school of interpretation

prioritises what parties actually intended; uses travaux préparatoires; weakness: intentions are often unclear, contradictory, or inaccessible to later-joining States

Teleological school of interpretation

prioritises object and purpose; interpretation should serve the treaty's goals; associated with human rights courts and the "living instrument" doctrine; weakness: too much judicial discretion, risks binding States to obligations they never consented to

Living instrument doctrine

the ECHR should be interpreted as a living instrument evolving with contemporary standards; applied by the European Court of Human Rights; the most developed application of evolutionary/teleological interpretation

Presumption of validity

a treaty is presumed valid once concluded; invalidity is the exception; the VCLT grounds are exhaustive

Relative invalidity

defects that only the affected State can invoke and can be waived by subsequent conduct; includes error, fraud, and corruption

Absolute invalidity

defects so fundamental that no subsequent consent can cure them; renders the treaty void not merely voidable; includes coercion of a representative, coercion of a State, and conflict with jus cogens

Error (Article 48)

a State may invoke error if it relates to a fact forming an essential basis of consent; cannot be invoked if caused by the State's own conduct or if it contributed to the error; acquiescence bars the claim

Fraud (Article 49)

if induced to conclude a treaty by fraudulent conduct of another negotiating State, the State may invoke fraud to invalidate consent; rare in practice

Corruption (Article 50)

if a State's representative is corrupted by another negotiating State, the State may invoke corruption to invalidate consent; extremely rare in practice

Coercion of a representative (Article 51)

consent procured by coercing the State's representative personally renders the treaty void; absolute ground

Coercion of a State (Article 52)

a treaty is void if its conclusion was procured by the threat or use of force in violation of the UN Charter; applies prospectively not retroactively; one of the most significant provisions

Jus cogens and invalidity (Article 53)

a treaty conflicting with a peremptory norm at the time of conclusion is void; no agreement between States can override jus cogens regardless of consent

Article 64 VCLT

if a new jus cogens norm emerges after a treaty is concluded, the treaty becomes void prospectively; obligations already performed don't retroactively become unlawful

Separability (Article 44)

invalidity affecting only specific clauses may allow those clauses to be severed with the rest of the treaty remaining in force; unless the clauses are so fundamental the rest wouldn't have been agreed without them

Termination by consent (Article 54)

the cleanest form of termination; through express treaty provision, agreement of all parties, or implied right of withdrawal depending on the nature of the treaty

Material breach (Article 60)

a material breach by one party entitles other parties to suspend or terminate; defined as repudiation of the treaty or violation of a provision essential to its object and purpose

Material breach in bilateral treaties

the innocent party may invoke the breach to terminate or suspend the treaty between them

Material breach in multilateral treaties

other parties unanimously may suspend or terminate; a specially affected State may suspend between itself and the defaulting State; any party may suspend for itself if the breach radically changes everyone's position

Humanitarian exception to material breach

material breach cannot be invoked to suspend humanitarian treaty provisions, particularly the laws of war and human rights obligations; these protect individuals, not States, so reciprocity doesn't apply

Supervening impossibility (Article 61)

if the object indispensable for execution permanently disappears or is destroyed, a party may invoke impossibility to terminate; cannot be invoked if the impossibility resulted from the invoking party's own breach

Rebus sic stantibus / fundamental change of circumstances (Article 62)

a fundamental change may only be invoked if: the circumstances were essential to consent at conclusion, the change radically transforms remaining obligations, and the change was not foreseen; cannot be invoked for boundary treaties or if caused by the invoking party's own breach

Why the Article 62 bar is so high

if States could exit treaties whenever circumstances changed inconveniently, treaty obligations would be meaningless; the VCLT deliberately makes this ground almost impossible to successfully invoke to protect treaty stability

Termination vs. suspension

termination ends the treaty permanently; suspension temporarily releases parties from performance without ending the treaty; suspension preferred when the situation might be reversible

Qatar v. Bahrain (ICJ, 1994)

minutes of a meeting signed by foreign ministers treated as a binding international agreement; Court examined language, context, and conduct; established substance over form principle: the label "minutes" was irrelevant, the content created binding obligations

Aegean Sea Continental Shelf (ICJ, 1978)

joint press communiqué between Greek and Turkish Prime Ministers held not to be a binding agreement to submit a dispute to the ICJ; political statement not intended to create legal obligations; contrasted with Qatar v. Bahrain to illustrate substance over form

Reservations to the Genocide Convention Advisory Opinion (ICJ, 1951)

abandoned the unanimity rule; adopted the object and purpose compatibility test; a State may be party to a multilateral treaty despite reservations if they are compatible with the treaty's object and purpose; codified in Article 19(c) VCLT; foundational case for the entire modern law of reservations

Temple of Preah Vihear (ICJ, 1962)

Thailand argued a map error invalidated a boundary treaty; Court rejected this partly because Thailand had accepted and used the map for decades; illustrates that acquiescence bars a State from invoking error under Article 48

Kasikili/Sedudu Island (ICJ, 1999)

dispute over an island in the Chobe River; good illustration of Article 31 applied step by step: ordinary meaning of "main channel," context of broader boundary treaty, object and purpose, subsequent conduct of the parties; found for Botswana

Costa Rica v. Nicaragua / Navigational and Related Rights (ICJ, 2009)

"commerce" in an 1858 treaty interpreted evolutionarily to include tourism; subsequent practice (Costa Rican tourist vessels without Nicaraguan objection) confirmed interpretation under Article 31(3)(b); key case for evolutionary interpretation and subsequent practice

Oil Platforms (Iran v. USA, ICJ, 2003)

interpreted commerce and fair and equitable treatment provisions of a 1955 Treaty of Amity in light of customary international law on use of force; key illustration of systemic integration under Article 31(3)(c)

Whaling in the Antarctic (Australia v. Japan, ICJ, 2014)

Japan's whaling program held not to be genuine "scientific research" under the Whaling Convention; IWC resolutions used as subsequent practice to mediate treaty interpretation; illustrates how non-binding soft law instruments interact with Article 31(3) interpretation

Fisheries Jurisdiction (ICJ, 1973)

Iceland tried to invoke changed circumstances (fish stock depletion) to escape obligations under a 1961 treaty; ICJ rejected this; illustrates the extremely high bar for rebus sic stantibus under Article 62; change in fish stocks didn't radically transform Iceland's treaty obligations

Namibia Advisory Opinion (ICJ, 1971)

League of Nations mandate concepts must be interpreted in light of "the international law of today" rather than 1920; foundational statement of evolutionary interpretation by the ICJ.

The fundamental tension of international environmental law

The climate works as one global system, but Earth’s surface is separated into sovereign state territory

Common but differentiated responsibilities (CBDR)

while all nations share a duty to protect the environment, their specific obligations and capacities to do so vary based on their historical contributions to environmental degradation

North-South divide

The global north (more developed countries) have already industrialized, spending the last ~200 years developing and emitting greenhouse gases, while the global south is just beginning to have the opportunity to industrialize and develop.

Right to development

States in the global south argue that they are entitled to industrialize and enjoy economic development.

Annex I States

includes industrialized (developed) countries with binding greenhouse gas (GHG) emission reduction targets

Attribution problem

it is difficult to assign legal responsibility for emissions, as they are often the result of private actors within States.

Due diligence

requires States to employ their best efforts and all available means to prevent, reduce, and control transboundary environmental harm, especially as carried out by private actors within their territory

Top-down approach

based on the traditional model of international law, where states negotiate, agree to treaties, and enforce obligations mutually through clear legal mechanisms; can be difficult to reach consensus

Bottom-up approach

the Paris approach, that allows for states to self-declare the commitments and contributions that they wish to take on; allows for greater flexibility but requires transparency and has less accountability mechanisms

Conference of the Parties (COP)

nearly 200 countries gather annually to negotiate climate action, review emissions targets, and coordinate global responses to global warming

Non-Annex 1 States

includes developing nations with voluntary reduction goals that receive financial and technical support from developed countries

Bering Sea Arbitration (1893)

context: US claimed right to stop British and Canadian ships from hunting fur seals outside of its territorial waters, citing the duty to protect the endangered seals

decision: claim was rejected

significance: shows limits of unilateral environmental regulation and the problem of the sovereign state system

River Oder Case (PCIJ, 1929)

context: decision whether the International Commission on the Oder River’s jurisdiction extended to tributaries of the river

decision: international rivers create a community of interest for all riparian states (obligation to protect and right to usage)

significance: early precursor to the no-harm principle, with shared natural resources not exclusive to the state they exist in, but mutual property of all affected states

Smelter Arbitration (1938/1941)

context: smelter in Canada emitted fumes that harmed US farmland and forests

decision: Canada had failed to do its due diligence to prevent transboundary harm

significance: establishes no-harm principle

no-harm principle

no State has the right to use or permit the use of its territory in a manner that causes significant environmental damage to the territory of other States, or to areas beyond national jurisdiction

Lake Lanoux Arbitration (1957)

context: France wanted to divert waters from Lake Lanoux for hydroelectric power, but Spain argued they could veto due to it interfering with the waters of the Carol river (which Lanoux flowed into)
decision: France could do what it wanted with the lake, but had to notify and consult with Spain and return the water. Spain could not veto the decision.

significance: importance of notification / consultation for cooperation, but also sovereignty.