On 24 October 2020, Honduras became the 50^th State to ratify the Treaty on the Prohibition of Nuclear Weapons (TPNW), thereby triggering Article 15(1) of the TPNW. With the fulfillment of the entry into force under Article 15(1) by 50 State ratifications, the TPNW is set to enter into force on 22 January 2021. The International Campaign to Abolish Nuclear Weapons (ICAN), which has been spearheading efforts to lobby States to sign the TPNW, said this signals ‘a new chapter for nuclear disarmament’. The TPNW is the first legally binding instrument to prohibit nuclear weapons. Its ultimate goal is their total elimination. The TPNW aims to fulfill this goal by ‘verifying the irreversible elimination’ of a State’s nuclear weapons programme. However, the TPNW fails to mention or appoint any international organisation to verify the elimination process.

Tytti Erästö, Ugnė Komžaitė, and Petr Topychkanov emphasise that a competent international authority lies at the core of credible verification to ensure the impartial and trustworthy achievement of any disarmament treaty. Consider the case of verification duties under the Chemical Weapons Convention undertaken by the Organisation for the Prohibition of Chemical Weapons (OPCW), an international organisation. Even though the OPCW undertakes activities based on State Party consent, the verification process including on-site inspections is undertaken by an independent inspectorate. This builds trust amongst the State Parties. In this way the States always look to the OPCW for its ‘credible verification and analysis.’ At the same time, disarmament verification is the most controversial issue between States and this also applies to the TPNW.

Article 4 TPNW: Core of elimination
Before the TPNW formally enters into force on 22 January 2021, one question remains unanswered: what is/will be the status of the 'competent international authority' under Article 4 of the TPNW? The answer to this question lies in the core objective of the TPNW.

Article 4 TPNW addresses the issue of verification by dividing the State Parties into two groups, but subjects both groups to an unnamed ‘competent international authority’. The first group of States are those which have dismantled their nuclear-weapons programme before joining the TPNW. The second group are the States which have not dismantled their nuclear weapons before joining the TPNW. This second group needs to undertake verifiable dismantlement as soon as possible. On an initial reading of Article 4, it is clear that the verification process does not take a ‘straight-line’ approach. Vagueness allows for a combination of different verification regimes to be tailored specifically for each State.

Negotiators of the TPNW have assigned the verification duties to a 'competent international authority' (see Art. 4 TPNW). To date, States have not designated a competent international authority under Article 4(6) to negotiate and verify the irreversible elimination of the nuclear weapons programme. Additionally, the TPNW provides no clear definition of the term ‘competent international authority’. Some writers wish to assign the TPNW verification function to the International Atomic Energy Agency (IAEA). At the same time, it is clear that the IAEA does not have a mandate to undertake dismantlement of military nuclear weapons programmes. Before State Parties assign the verification function duties to the IAEA, they must consider the functional limits of international organisations as summarised by Henry Schermers and Niels Blokker in the book International Institutional Law (2018 edition): ‘international organisations can only perform duties as far as powers have been attributed to them by the member States’. Therefore, any implied expansion of the IAEA’s mandate is not possible. For the IAEA to be considered as a candidate for the verification duties under Article 4 TPNW, its mandate needs to be amended under Art XVIII of its Statute.

A new international organisation
The IAEA is a good starting point for the TPNW mandated verification. But given the constraints in the IAEA set-up, the second option advocated by many and perhaps the only option, is to create a new international organisation.

Creating a new international organisation is easier said than done. As advocated by Tamara Patton, Sébastien Philippe, and Zia Mian in ‘Fit for Purpose: An Evolutionary Strategy for the Implementation and Verification of the Treaty on the Prohibition of Nuclear Weapons’, the creation of a new international organisation should follow the phased evolutionary strategy. This would provide some level of flexibility and time to adapt to individual States’ dismantlement requirements.

Phase I will be triggered by the meeting of the State Parties. They will need to create a basic institutional structure that is backed by a scientific advisory committee like the Scientific Advisory Body in the OPCW. This committee should be able to understand and advise the States on nuclear life cycles and issues of nuclear forensics. A strong scientific foundation will ensure that the new international organisation finds the perfect synergy between modern technology, human interference-based verification, verification technology, and non-verification based technology.

Phase II will be triggered when a nuclear-weapon State ratifies the TPNW. Even though the five nuclear-weapon States under the Treaty on the Non-proliferation of Nuclear Weapons (NPT) have refused to sign or ratify the TPNW, it is important for the future Article 4 organisation to at least be able to test its dismantlement capabilities. First, the new organisation needs to ensure a detailed reporting and declaration mechanism. This mechanism will form the basis for inspections and ultimately lead to dismantlement programmes. Moreover, the Article 4 organisation needs to be backed by competent inspectors and staff to oversee the entire dismantlement procedure.

When the aims and objectives of Articles 2 and 4 TPNW have been fulfilled, Phase III will come into operation. Even after Phase II has been achieved, it is imperative to ensure that the Article 4 organisation does not become redundant. Instead, it should hold a limited role that aims to prevent the re-emergence of nuclear weapons. The continuing presence of the verification capabilities of the new international organisation should be able to deter States from developing nuclear weapons, thereby sustaining a nuclear-free world. Finally, the new organisation’s verification division could become a depository of information for future reference, which will guide efforts to improve technology.

Conclusion
As stated by many, compliance with any disarmament treaty can only be assured through effective verification. Through the new international organisation, therefore, the TPNW must be able to carry out effective verification and ensure full compliance with Article 4. When the TPNW finally enters into force, the State Parties will have their work cut out. On a similar line to Dr. Thomas Shea, the author also shares concerns about the ability of the State Parties to work together and reach an agreement concerning verification provisions.