On 14 February 1967, at Mexico, Federal District, the Treaty for the Prohibition of Nuclear Weapons in Latin America was signed — the original UNTS I-9068 title, not the later formula “and the Caribbean”. COPREDAL approved the draft two days earlier; the opening for signature is this day. The plenipotentiaries sign on behalf of their Governments; Alfonso García Robles, a Mexican diplomat, led the preparation and received the Nobel Peace Prize in 1982. Authentic texts: Spanish, French, English, Portuguese, Chinese, Russian. Depositary: the Government of Mexico. The instruments DONE formula is not copied.

Article 28: entry into force, in principle, after ratification by the States in Article 25, Additional Protocol I by extra-zonal States with territories in the zone, Additional Protocol II by the nuclear-weapon Powers, and IAEA safeguards agreements. Signatories have an imprescriptible right to waive those requirements, wholly or in part, by a declaration annexed to ratification. UNTC: 22 April 1968, as between Mexico (20 September 1967) and El Salvador, which used the waiver. Brazil ratified on 29 January 1968 without availing itself of it. Wikipedia also gives 25 April 1969; we follow the UNTS note. After eleven States, the Depositary shall convene a preliminary meeting so that the Agency may begin its work.

Article 1: the Parties undertake to use exclusively for peaceful purposes the nuclear material and facilities under their jurisdiction and to prohibit, in their territories, the testing, use, manufacture, production or acquisition of nuclear weapons, as well as the receipt, storage, installation, deployment or any form of possession. This is not a weapons catalogue. Article 3: territory includes the territorial sea and air space. Article 4: the zone is first the territories for which the Treaty is in force; upon fulfilment of Article 28(1) it also covers the western-hemisphere area described, except the continental part of the United States — without reproducing the coordinates.

Article 7: there is established the Agency for the Prohibition of Nuclear Weapons in Latin America, with headquarters in Mexico City; later OPANAL. Only the Contracting Parties are members. The General Conference is the supreme organ; the Council has five members. Article 13: each Party shall negotiate with the IAEA for the application of safeguards to its nuclear activities. Article 27: no reservations. This is not an inspection handbook.

The annexed Protocols are not the Treaty itself. Protocol I: extra-continental or continental States with responsibility for territories in the zone shall apply the denuclearization statute to those territories. Protocol II: the nuclear-weapon Powers undertake to respect the zone. The United Kingdom signed both on 20 December 1967; the other extra-zonal ratifications are later. Cuba signed only in 1995 and ratified in 2002.

The 1959 Antarctic Treaty was a zone over an uninhabited area; this is the first over a populated region. The 1968 NPT is a distinct, later instrument. Amendments that add “Caribbean” to the title belong to the General Conference, not to the Tlatelolco day.

Cover: Plaza de las Tres Culturas in Tlatelolco, the district of signature — the photograph is of the square, not the table. Wikimedia Commons, free licence.

For context: Treaty of Tlatelolco. The text: Treaty for the Prohibition of Nuclear Weapons in Latin America (UNTS I-9068).