The core principles of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) are to prevent the development and acquisition of nuclear weapons, and to reach complete disarmament. But, argues Cecilia Gustavsson, without improved transparency and independent verification mechanisms, the NPT could, paradoxically, accelerate a new nuclear arms race
Under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) there are five original nuclear-weapon states (NWS): US, USSR/Russia, UK, France and China. These countries developed their nuclear weapons before negotiation of the NPT, and they use deterrence theory to justify possession.
Deterrence theory holds that if both sides can retaliate after a nuclear strike, neither will initiate one, given that mutual destruction is the outcome. Yet, deterrence theory remains controversial. Some proponents argue that broader possession of nuclear weapons globally could increase global stability through mutual deterrence. However, this view has not gained widespread acceptance.
Hence, even though NWS embrace deterrence policy for their own protection, they also advocate the NPT. So do most of the world’s countries, which have consequently signed the NPT promising not to acquire their own nuclear weapons.
This raises a fundamental contradiction: how can nuclear weapons be seen as a source of peace when held by some, yet a threat when sought by others?
Scholars often apply deterrence theory to the US-Soviet/Russia power axis. One could argue that deterrence has worked, since the two have so far avoided major conflicts. Several times during the Cold War, both sides issued nuclear threats. Mercifully, they never acted upon them. This may have been because of the threat of mutual annihilation – but that is unlikely to be the only factor. The US had clear military dominance during the first part of the Cold War, until the early 1970s. Hence, for more than 20 years, it also had the upper hand in nuclear capability. Conflict was therefore avoided not solely because of the fear of nuclear retaliation.
Russia has recently issued direct or indirect nuclear threats to NPT signatories Ukraine, Finland, Poland, Estonia, and Sweden. This has created tension in the NPT community
There are, however, cases where NWS have threatened to use nuclear weapons on non-nuclear states. This kind of reverse-deterrence policy aims to force a militarily weaker opponent into submission. The US has, over time, issued threats (interpreted as nuclear threats) towards Korea, Vietnam, Iraq, and Iran. Iraq and Iran were signatories of the NPT when the threats were issued. Russia has recently, directly or indirectly, threatened Ukraine, Finland, Poland, Estonia, and Sweden (all NPT signatories) with nuclear weapons. This creates severe tension in the NPT community, and risks countries losing confidence in the treaty.
It is well known that Ukraine gave up its nuclear arsenal to Russia in exchange for safety guarantees and respect for its sovereignty and territorial integrity. Instead, Ukrainians have suffered invasion and threats from a nuclear superpower. These threats, and the unpredictability of how some NWS could act, might push more countries towards acquiring nuclear weapons. An important factor for remaining in the NPT, therefore, is trust that the NWS' military capability will also protect non-nuclear states; that it will not be used against those who have refrained from developing nuclear weapons of their own.
The NPT has several articles, mainly about the non-proliferation of material, technology and knowledge. But there is also one article (Article VI) about disarmament:
Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control
Extensive monitoring of compliance is in place regarding non-proliferation. There is, however, no international framework for monitoring disarmament. Observers often point out that Iraq and Iran, for example, are not fully compliant with the NPT. But are all NWS compliant? It is, in fact, possible to severely violate Article VI with no consequences for the violators. Presently the NWS are updating their arsenals instead of disarming them. This might lead to an increased arms race — and even to new de facto nuclear-weapon states.
It is important to point out that some disarmament has taken place. Today, there are less than 20% as many deployed nuclear warheads globally as during the height of the Cold War. Several bilateral agreements have existed between US and the USSR/Russia. The latest, New START, still formally holds until 2026; however, Russia paused it in 2023.
Clearly, nuclear disarmament is possible, but at the whim of the superpowers. Several of the agreements collapsed before their end date, or even before their start date. In this fragile system, the initiative is entirely in the hands of the NWS. Other countries have no place at the negotiations, nor any right to perform inspections of verification. Consequently, non-nuclear countries advocate for transparency and multilateral negotiations.
To preserve its relevance, the NPT must be modernised to address not only non-proliferation, but verifiable disarmament
So, what we need is compliance with Article VI. But how can we ensure this without transparency and independent observers? Verifying disarmament is difficult. The physical signature of a nuclear weapon is weak and ambiguous, especially to non-nuclear-weapon states with no firsthand experience. It becomes even more difficult with the information barriers and secrecy which define the non-proliferation agreement.
To preserve its relevance, the NPT must be modernised to address not only non-proliferation, but also verifiable disarmament. This would require greater transparency, independent verification mechanisms, and a renewed commitment from nuclear-weapon states. Without these reforms, the treaty risks losing credibility — potentially accelerating a new global arms race rather than preventing one.
