9.6 Interpretation and Travaux Préparatoires

The general rule (Article 31 — the interpretive charter): a treaty shall be interpreted (1) in good faith; (2) according to the ordinary meaning of the terms; (3) in their context; (4) in the light of the treaty's object and purpose — a single integrated operation, not a hierarchy of steps. The context includes text, preamble, annexes, related instruments (Art. 31(2)); subsequent practice and subsequent agreements as authentic interpretation's living elements (Art. 31(3)); the special-meaning rule (Art. 31(4) — the parties' special usage prevails). Supplementary means (Article 32 — where the travaux live): travaux préparatoires — the negotiating history (drafts, records, committee reports) and the circumstances of conclusion — to confirm the Article 31 result, or where that result is ambiguous or manifestly absurd/ unreasonable. The doctrine's politics: textualists (object-and-purpose) vs. intention-seekers (travaux) — Article 32's placement of travaux as supplementary marks the textualist victory; the ICJ uses travaux freely in confirmation (Gabčíkovo, Kasikili/Sedudu). The maxims (the supplementary toolkit): effet utile (effectiveness); lex specialis derogat legi generali; harmonious reading; the presumption against derogation from sovereignty without clear words.