The Treaty on the Prohibition of Nuclear Weapons: old wine, new bottle?

The Treaty on the Prohibition of Nuclear Weapons officially entered into force on 22 January 2021, prompting public applause by organisations such as the International Committee of the Red Cross (ICRC) and a countdown celebration by The International Campaign to Abolish Nuclear Weapons (ICAN). Having attracted this much attention, the question of how far the Treaty actually goes and whether such celebrations are warranted is imperative to assessing its value. In this article, I argue that, while the Treaty deserves recognition for its achievements, it is questionable whether the Treaty actually amounts to much in terms of complete disarmament.

Cause for celebration

For starters, the Treaty trumps its predecessor nuclear weapons treaties in that it is the first international legal instrument that prohibits the use, development, production, stockpiling, and testing of nuclear weapons (Article 1(1)(a)). It unequivocally states that nuclear weapons must never be deployed, tested, produced, manufactured, otherwise acquired, possessed, or stockpiled ‘under any circumstances, stressing that their prohibition is the only way to guarantee complete elimination. This marks an unprecedented step towards the complete removal of nuclear weapons. The Treaty acts further by prohibiting not only the ‘use or threat’ of nuclear weapons but also assistance, encouragement, inducement, transfer, and receipt of nuclear weapons—a comprehensive step that seeks to universally eliminate these weapons.

Article 12 of the Treaty also promotes universal ratification by providing that “Each State Party shall encourage States not party to this Treaty to sign, ratify, accept, approve or accede to the Treaty, with the goal of universal adherence of all States to the Treaty”—something that has not been expressly included in previously-concluded nuclear weapons treaties.

Moreover, the new Treaty leaves no room for vague interpretations when it comes to nuclear disarmament, unlike its predecessor. The predecessor Non-Proliferation Treaty (NPT) requires States to pursue negotiations in good faith leading to complete nuclear disarmament under Article VI. The Security Council likewise has pushed for the negotiation in good faith of treaties for nuclear weapons elimination in resolutions 984 and 1887. This good faith obligation has been disregarded by nuclear-weapon states. The 2016 Judgment on the Obligations concerning Negotiations relating to Cessation of the Nuclear Arms Race and to Nuclear Disarmament (the Marshall Islands v. the United Kingdom) by the ICJ reveals just how poorly this obligation has been fulfilled. Although the Court could not proceed in its judgment for lack of jurisdiction, the (near-)tied votes between the judges’ ruling on jurisdiction (para. 59(1)) presents a small win in recognising the Marshall Islands’ claim. Likewise, the Court’s recognition of its 1996 Nuclear Weapons Advisory Opinion reaffirms that “there exists an obligation to pursue in good faith and bring to a conclusion negotiations leading to nuclear disarmament in all its aspects under strict and effective international control” (para. 21). Moreover, the controversy behind Article VI and whether it creates an obligation to conclude negotiations (obligation of result) or merely attempt to do so is relieved by the new Treaty which brings to life the Article VI obligation by prohibiting nuclear weapons and their related activities for State Parties.

The Treaty remedies what its predecessor has failed to do. The NPT was developed to limit ‘rogue’ states from developing and proliferating nuclear weapons by creating a compromise. Nuclear weapon states would promise not to use their nuclear weapons against other states if non-nuclear weapons states agreed not to develop or proliferate nuclear weapons themselves. This double standard has undermined negotiation efforts on the complete elimination of nuclear weapons. For example, Jaswant Singh, a Member of Parliament to the Bharatiya Janata Party and Senior Adviser on Defense and Foreign Affairs to Indian Prime Minister Atal Bihari Vajpayee has publicly criticised this nuclear apartheid and unfair security leverage: “if the Permanent Five continue to employ nuclear weapons as an international currency of force and power, why should India voluntarily devalue its own state power and national security?”(page 43). By creating this dichotomy of nuclear and non-nuclear-weapon states, the NPT undermines efforts of disarmament and international security. The new prohibition instead removes this divide and preferential treatment by requiring all State Parties to refrain from acquiring nuclear weapons. By placing all states on an equal footing, the Treaty expresses the unequivocal need to eliminate nuclear weapons in order to ensure true collective security and a ‘nuclear-weapon-free world.’

The Treaty’s adoption and entry into force act as a reminder of the importance of the efforts of non-state and civil society actors campaigning for change. For example, it was the relentless campaigning by civil society actors against blinding lasers and anti-personnel landmines that influenced public debate which eventually led to the ban on such weapons. The nuclear prohibition likewise was advocated for by the ICAN and the ICRC individually, and at intergovernmental conferences such as the Second Conference on the Humanitarian Impact of Nuclear Weapons.

Furthermore, the new Treaty overcomes some of the mixed signals eschewed by the ICJ’s more than confusing Advisory Opinion on the legality of nuclear weapons. The ICJ’s recognition of the Lotus principle finds that in the absence of a prohibitive rule in international law, States are free to act as they wish (para. 21). The ICJ determined that since there is no customary or conventional international law allowing “any specific authorization” nor “any comprehensive and universal prohibition” of the use or threat of nuclear weapons (para. 105(2)), the possibility of the threat or use of nuclear weapons was left open in the “extreme circumstance of self-defence.” The new Treaty surmounts this vague exception by creating an outright prohibition for the first time, meaning that State Parties may no longer evade the legality question even in the extreme case of self-defence.

Why we shouldn’t celebrate

However, the Treaty shouldn’t be celebrated just yet. For starters, the nine nuclear weapon states themselves have not ratified or signed the Treaty. The Treaty is largely ratified by the Global South and small island states who are disproportionately affected by nuclear testing conducted by the nuclear powers. So, while the Treaty presents two steps forward, it also goes one step back in that it doesn’t resolve the issue of nuclear weapon states maintaining leverage over the international community. Indeed, the US has exerted public pressure by calling out states who have signed the treaty and calling their decision “a strategic error” in an open letter. Perhaps the fact that the US feels threatened by this Treaty coming into force should be celebrated as evidence of victory.

Still, the Treaty cannot be seen as an end itself, but rather a means to an end. With nuclear weapons states refusing to sign the Treaty nor accept its potential to develop into customary international law in the future, the Treaty doesn’t seem to change the nuclear landscape very much since the very States that possess nuclear weapons are not interested in elimination. Nor will pressure by the State Parties to the new Treaty be solid enough to discourage nuclear weapon states from operating. This is because nuclear weapons, unlike landmines and blinding lasers, have the capacity to annihilate a significantly large number of people, have centuries-long effects like long-term radiation and environmental contamination, and operate as significant deterrents by virtue of their mere possession. Therefore, while other arms prohibitions have led to universal elimination, as was the case with the 1925 Geneva Protocol which preceded the Chemical Weapons Convention, nuclear weapons present a unique challenge to absolute prohibition because of the perceived need for deterrence from a national security point of view outweighs public pressure by civil society actors or States.

The Treaty’s plan to prohibit and eliminate State Parties’ nuclear weapons by requiring their immediate removal from operational status and further destruction “as soon as possible” (Article 4(2)) is progressive. However, with major powers already reluctant to prohibit, let alone eliminate existing nuclear weapons, the Treaty’s ambitious goals fail to redress the inequality that was born out of the Cold War power distribution. If anything, it makes the inequality more apparent since States disproportionately affected by nuclear explosions have willingly committed themselves to nuclear elimination while nuclear weapons states continue resisting efforts.


There is no doubt that the Treaty on the Prohibition of Nuclear Weapons represents a valuable step forward in the fight against nuclear proliferation and armament by making clear its intention of complete nuclear prohibition. That being said, the absence of meaningful participation by powerful nuclear weapon states in the Treaty highlights its futility, for the very States who have influence over nuclear decisions are not bound by any prohibitive rule, nor are there any signs suggesting that this become customary international law, given the outright rejection of the Treaty by those very states. For this reason, until the Treaty is ratified by the influential nuclear states, it remains old wine in a new bottle.


Layal Alghoozi is a graduate of the University of Glasgow.