In 2009, the United Nations General Assembly declared 29 August the International Day against Nuclear Tests to increase awareness and education about the effects of nuclear weapon test explosions or any other nuclear explosions and the need for their cessation as one of the means of achieving the goal of a nuclear-weapon-free world.

The International Day against Nuclear Tests and the upcoming 70th Anniversary of the first mainland test in Australia are opportunities for all Australians to refocus efforts on the humanitarian impacts of nuclear weapons and the role of the Treaty on the prohibition of Nuclear Weapons in building on the existing disarmament architecture, including the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and driving progress on international cooperation to support communties impacted by nuclear weapons testing. 

Beginning in 1952 the British government, with agreement from the Australian government of the day, began a regime of nuclear weapons testing in Western Australia’s Monte Bello Islands, and at Emu Field and Maralinga in South Australia. 

These tests saw fallout over much of the Australian mainland and further into the Pacific. The impacts of these tests have disproportionately affected many First Nations groups, who have cared for this country for many thousands of years.

Today, the legacy of British nuclear weapons testing in Australia continues to unfold. Survivors suffer from higher rates of cancer than the general population due to their exposure to radiation. Only a few have ever been compensated. Much of the traditional lands used for the blasts remain radioactive and off-limits to this day.

Australia brought the Comprehensive Nuclear-Test-Ban Treaty (CTBT) text into the UN General Assembly for endorsement in 1996 and ratified the CTBT in 1998. Australia continues to lead resolutions on the CTBT in United Nations fora.  The current Director-General of the Comprehensive Test Ban Treaty Organisation (CTBTO) is Australia diplomat Dr Robert Floyd.

Nuclear testing is also prohibited by the various regional nuclear-weapon-free zone treaties, including the South Pacific Nuclear Free Zone Treaty (Treaty of Rarotonga), which Australia ratified on 11 December 1986, which enabled its entry into force. 

Under Article 6 of the Treaty of Rarotonga, Australia has made a legal undertaking “[t]o prevent in its territory the testing of any nuclear explosive device” and “[n]ot to take any action to assist or encourage the testing of any nuclear explosive device by any State”.

The Treaty on the Prohibition of Nuclear Weapons was drafted to work in complementarity with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and all other international disarmament instruments, including the Nuclear-Non-Proliferation Treaty.

The nuclear-weapon-free zone treaties, the CTBT and the TPNW all work together to reinforce the global norm against all forms of nuclear testing.  The TPNW’s legally binding prohibition on nuclear testing is especially important given that the CTBT is not yet binding on the states that have ratified it as pending its ratification by certain specified states, it has not yet entered into force.

Australia has yet to join the Treaty on the Prohibition of Nuclear Weapons, despite joining all other relevant nuclear disarmament agreements. How do the CTBT and TPNW compare and compliment each other?

When the CTBT was originally developed, explosive nuclear testing was a key step in the development of new types of more sophisticated and thermonuclear nuclear weapons, and thus a ban on test explosions was hoped to be a significant non-proliferation measure, impeding the development of new types of weapons. 

However, by the 1990s, non-explosive testing of nuclear weapons through computer simulations and various laboratory-based methods, including hydrodynamic and hydronuclear testing, enabled the development and deployment of new types of nuclear weapons without them being explosively tested. 

France, for example, only ended its Pacific nuclear test explosions once it was confident it had developed non- explosive testing methods sufficiently for new weapons development. Thus while ending nuclear test explosions avoids substantial long-term health and environmental harms, its effectiveness as a non-proliferation measure has largely been lost.

Prior to the adoption of the TPNW, nuclear weapons were the only weapons of mass destruction not subject to a categorical ban, despite their catastrophic humanitarian consequences. The new agreement thus fills a major gap in international law.

History shows that the prohibition of certain types of weapons facilitates progress towards their elimination. Weapons that have been outlawed by international treaties are increasingly seen as illegitimate, losing their political status.

Arms companies find it more difficult to acquire funds for work on illegal weapons, and such work carries a significant reputational risk. Banks, pension funds and other financial institutions divest from these producers.

The nuclear weapon ban treaty complements the prohibitions on biological and chemical weapons, land mines and cluster munitions, and reinforces various other legal instruments on nuclear weapons, including the non-proliferation treaty of 1968.

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a treaty to ban nuclear weapons test explosions and any other nuclear explosions.

The CTBT contains provisions in relation to the development of monitoring stations, on-site inspections and confidence-building measures which contribute to the global verification regime.

The Treaty on the Prohibition of Nuclear Weapons reinforces the normative pressure on States to make progress on nuclear non-proliferation and disarmament, including the ratification of the CTBT.

The TPNW includes a specific reference to the CTBT in its preamble, which recognises the vital importance of the Comprehensive Nuclear-Test-Ban Treaty and its verification regime as a core element of the nuclear disarmament and non-proliferation regime.

The TPNW preamble also acknowledges the “unacceptable suffering and harm” caused to people as a result of nuclear testing, and “the disproportionate impact of nuclear-weapon activities on indigenous peoples”.

While the CTBT welcomes reductions in arsenals of nuclear weapons, and the prevention of nuclear proliferation in all its aspects, it does not prohibit or outlaw the possession of nuclear weapons.

The TPNW prohibits nations from developing, testing, producing, manufacturing, transferring, possessing, stockpiling, using or threatening to use nuclear weapons, or allowing nuclear weapons to be stationed on their territory. It also prohibits them from assisting, encouraging or inducing anyone to engage in any of these activities.

186 states have signed and 174 have ratified the CTBT. But the treaty is not yet in force. 

The CTBT requires 8 additional specific states* to ratify before the treaty can enter into force and take legal effect. Regrettably, action by these states appears unlikely for the foreseeable future. 

* States that have not ratified the CTBT, but must do so for the treaty to enter into force: China (People’s Republic of), Democratic People’s Republic of Korea (North Korea), Egypt, India, Iran, Israel, Pakistan and the United States.

The TPNW entered into force in 2021. It has been signed by 92 and ratified by 68 states to date.

The CTBT does not contain positive obligations for states parties to support victims of nuclear testing or remediate impacted environments. 

Article 6 of the TPNW requires states parties to provide victim assistance and environmental remediation to individuals and areas under their jurisdiction or control affected by the use or testing of nuclear weapons.

The TPNW supports, builds on and extends the provisions of the CTBT, contributing to the overlapping, mutually reinforcing international architecture against explosive nuclear testing, and supporting nuclear non-proliferation and disarmament.

The broader and more comprehensive prohibitions in the TPNW are all the more important as it has entered into legal force, whereas there is no foreseeable prospect of the CTBT doing so.

Further, the TPNW’s comprehensive and categorical prohibitions on nuclear weapons activities fulfil and extend the CTBT’s hoped-for non-proliferation benefits.