# Vienna Convention on the Law of Treaties **Status: stub — expand.** Concluded at Vienna **May 23, 1969**, in force **January 27, 1980** — the treaty about treaties. It codifies how international agreements are made, interpreted, amended, suspended, and terminated: the effect of signature (Art. 18 — an obligation not to defeat the object and purpose before ratification), the rules on reservations (Arts. 19–23), *pacta sunt servanda* and the bar on invoking domestic law to excuse breach (Arts. 26–27), the interpretive method (Arts. 31–33), and the grounds and procedures for withdrawal (Arts. 54–62), including the default rule that a treaty with **no withdrawal clause** generally may not be exited unilaterally. **The United States signed in 1970 and has never ratified it.** The Senate has never voted; it sits with the other long-pending items on the [[Senate Foreign Relations Committee]] calendar. The State Department nonetheless treats most of the Convention as declaratory of customary international law and applies it in practice — a standing example of the gap between what the United States is bound by and what it has consented to. Do not confuse it with the **Vienna Convention on Consular Relations** (1961/1963), the separate instrument at issue in [[Medellín v. Texas]]. ## See also - [[How a Treaty Is Made and Ratified]] - [[International Law Hub]] - [[Medellín v. Texas]] - [[UN Charter]]