Abstract/Summary

Various limitations on the testing of nuclear weapons already exist within international law, including the Partial Test-Ban Treaty of 1963, along with further restrictions on where testing is permitted, and the maximum yield of such tests. Yet it was not until 1996 that the Comprehensive Test-Ban Treaty (CTBT) was adopted, the first attempt to prohibit all forms of testing that result in a nuclear weapon ‘explosion’. The CTBT does not, however, cover computer simulated and sub-critical nuclear tests, which can ensure the safety and reliability of existing stockpiles, thus undermining the CTBT’s implications for nuclear disarmament. More importantly, due to the onerous entry-into-force requirements under Article XIV, the CTBT is not yet binding on states, and is unlikely to become so in the near future. A further contribution to the legal restrictions on nuclear weapon testing has recently been provided by the Treaty on the Prohibition of Nuclear Weapons (TPNW), which was adopted in July 2017. Under Article 1(1)(a), state parties undertake never under any circumstances, to ‘develop’ or ‘test’ nuclear weapons or other nuclear explosive devices’. Given the challenges facing the CTBT, this Article seeks to analyse the extent of the testing prohibition established under Article 1(1)(a), as well as the scope of the prohibition of development in order to determine whether the TPNW closes the testing ‘loophole’ established by the CTBT by including sub-critical and computer simulated testing within either of these undertakings. The article will conclude by offering some thoughts on the TPNW’s prospects for entry-into-force and its future relationship with the CTBT.