Introduction

The establishment of Nuclear-Weapon-Free Zones (NWFZ) is a regional approach to strengthen global nuclear non-proliferation and disarmament norms and consolidate international efforts towards peace and security. The legal definition of the NWFZ is given by the General Assembly resolution 3472 B from 1975 and by the Guidelines and Principles for the Nuclear-Weapon-Free Zones as explained by the UN Disarmament Commission in its report of April 1999, based on Article VII of the NPT (Non-Proliferation Treaty).

In summary, a NWFZ is a multi-lateral treaty based on the initiation of the states of the zone to establish a zone free of nuclear weapons, with a content agreed among them, which includes a verification regime and the attached protocols, which include the Negative Security Assurances (NSAs) of the nuclear weapon states. A NWFZ may consist of the territory of any number of states, but even just a small part of a state’s territory can be acknowledged as a NWFZ. Typically, a NWFZ would cover a whole continent (as in the case of Latin America by the Tlatelolco Treaty, or Africa by the Pelindaba Treaty), but even one country can declare itself a NWFZ (as Mongolia did). The Treaty on the German unification states that the territory of the former German Democratic Republic will be free of nuclear weapons.

NWFZ treaties are special treaties in the sense that the multilateral treaty is amended by one or more protocols which include the negative security assurances by the nuclear weapon states, and which may include other obligations by countries outside the region (such as not to perform a nuclear test there or the obligation by states outside the region but with legal authority within, such as the former colonial powers).

Over many decades NWFZ treaties have undergone a constant evolution as they came to cover an increasing number of issues relating to specific regional concerns and a shifting international context. The first treaties to include any restrictions or prohibitions on military nuclear activities were typically covering spaces outside the authority of any state, such as the Antarctica, the Outer Space, the Moon and the Seabed, prohibiting the use for military purposes including the deposit of nuclear weapons there.

The first treaty established over territory belonging to the legal authority of states, the Tlatelolco Treaty included the prohibition of the “testing, use, manufacture, production or acquisition”, as well as “the receipt, storage, installation, deployment and any form of possession of any nuclear weapons”. But it maintained the right to the peaceful uses of nuclear energy, and established the OPANAL as the organization verifying the treaty. And – in harmony with the technical thinking of the time – it still allowed so-called peaceful nuclear explosions.

However, the prohibition of any nuclear explosion (be it peaceful or military) was added in the following treaties established in zones where nuclear testing by the nuclear power states were seen as a great concern. The NWFZ treaties after Tlatelolco have been furthermore expanded by such clauses as the early notification of accidents, the physical protection of nuclear materials and equipment, the prohibition of armed attacks on nuclear installations and of dumping nuclear wastes, mechanism for compliance, and the protection of the environment