The Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water was signed in Moscow on 5 August 1963, in triplicate, the English and Russian texts equally authentic. Plenipotentiaries: Dean Rusk (United States), Lord Home (United Kingdom) and Andrei Gromyko (USSR). Article III: open to all States; ratification; the three Original Parties are depositaries; it enters into force after ratification and deposit by all three — 10 October 1963. UNTS No. 6964, vol. 480. It is not the 1968 Non-Proliferation Treaty, nor the 1996 CTBT, nor the 1974 Threshold Test Ban Treaty.

The preamble seeks the discontinuance of all test explosions of nuclear weapons and an end to the contamination of the environment by radioactive substances, as a step towards an agreement on general and complete disarmament. Article I: each Party undertakes to prohibit, prevent and not carry out any nuclear-weapon test explosion, or any other nuclear explosion, at any place under its jurisdiction or control, in the atmosphere (including outer space) or under water (territorial waters or high seas), and in any other environment if radioactive debris is present outside the territorial limits of the State concerned — a framework, not a testing handbook. Paragraph 2: a duty to refrain from causing, encouraging or participating in such explosions.

Underground tests remain outside the prohibition in paragraph 1(a), subject to the transboundary-debris limit in 1(b); the treaty is not a comprehensive ban. Article II: amendments are proposed to the depositaries; a conference is convened at the request of one-third of the Parties; approval requires a majority of all Parties, including all Original Parties, and takes effect upon deposit of the corresponding ratifications.

Article III paragraphs 4–6: for later States, the treaty enters into force on the date of deposit; the depositaries inform of signatures, ratifications and accessions; registration pursuant to Article 102 of the UN Charter. Article IV: unlimited duration; withdrawal on three months’ notice if extraordinary events related to the subject matter of the Treaty have jeopardized supreme interests. Article V: archives with the depositaries; certified copies to the Parties.

Cover: the Grand Kremlin Palace in Moscow, the place of signature; we do not claim the signing room. Wikimedia Commons, free licence.

Sources consulted: Partial Nuclear Test Ban Treaty; Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water (UNTS 6964).