While the NPT is experiencing a credibility crisis, the future of the CTBT hangs in the balance. The expiry of the New START on 5 February 2026 marked the end of the arms control era. The nuclear taboo regarding the non-use of nuclear weapons is fast diminishing due to explicit nuclear threats by world leaders. The infusion of AI into nuclear decision-making, meanwhile, is likely to affect strategic stability.

The foundations of the global nuclear order are becoming increasingly fragile. According to Kjølv Egeland, nuclear order is portrayed as “a ‘pragmatic’ or ‘practical’ compromise between unconstrained nuclear anarchy, on the one hand, and prompt steps toward nuclear disarmament, on the other”.[1] For William Walker, the nuclear order during the Cold War was based on just two factors: “a managed system of deterrence, and a managed system of abstinence”.[2]

The United States and the Union of Soviet Socialist Republics (USSR), the predecessor of Russia, largely shaped the nuclear order that emerged around 1970. The two superpowers engaged in an unrestricted nuclear build-up until the 1962 Cuban Missile Crisis, when the world was brought back from the brink of nuclear exchange between the two countries. Though the intense rivalry persisted between the US and the USSR, there was mutual understanding regarding two aspects: one, the prevention of unwanted nuclear war and second, the prevention of nuclear proliferation, leading to the creation of multiple nuclear players.[3]

Although discussions about ways to inhibit nuclear weapons spread began in the late 1950s, they gained momentum because of the Cuban Missile Crisis, leading to the formation of the nuclear Non-Proliferation Treaty (NPT) in 1968. The International Atomic Energy Agency (IAEA), established in 1957, became the primary legal instrument for verifying that nations use nuclear technology exclusively for peaceful purposes.

Similarly, on the bilateral front, the two superpowers agreed to negotiate arms-control treaties governing various aspects of the arms race, beginning with the successful negotiation of the Anti-Ballistic Missile (ABM) Treaty in 1972 as part of the Strategic Arms Limitation Talks (SALT). Thus, the global nuclear regime, represented by the NPT and the IAEA, along with bilateral arms-control treaties, should be considered a fundamental pillar of the global nuclear order.

Apart from this regime, the US has played an important role in preventing nations from seeking nuclear weapons by providing a nuclear security umbrella in Asia and Europe. Though providing a nuclear umbrella was a calculated act during the Cold War years aimed at consolidating the US camp, it nevertheless contributed to non-proliferation efforts. Thus, extended nuclear deterrence became another essential pillar of the global nuclear order. Ultimately, the nuclear taboo—the deeply held international norm against the use of nuclear weapons—serves as the final pillar of the global nuclear order. According to Nina Tannenwald, nuclear taboo has been one of the reasons why the nuclear bomb has not been used since 1945.

Therefore, the state of the current global nuclear order can be assessed by the health of the following parameters: the international nuclear regime, bipolar nuclear hegemony, extended nuclear deterrence, and the nuclear taboo. Additionally, the emergence of Artificial Intelligence (AI) is likely to influence the future global nuclear order.

Withering of the Global Nuclear Regime

The cornerstone of global nuclear governance, the NPT, has long been perceived as unjust, even though 191 nations have ratified the Treaty and have largely held, so far.[4] The Treaty has laudable objectives of stopping the proliferation of nuclear weapons, promoting the peaceful use of the atom and moving towards comprehensive disarmament. Unfortunately, the Treaty’s ‘disarmament’ pledge has fallen by the wayside. Instead of achieving complete elimination of nuclear weapons, the Treaty has ended up formalising and legitimising possession of nuclear weapons by the Nuclear Weapons States (NWS).

Article VI of the NPT calls for the cessation of the arms race and for disarmament at an early date. Contrary to this pledge, countries are increasing their warhead numbers, although overall nuclear numbers have reduced compared to their peak during the Cold War. China’s rise is spectacular,[5] while France has declared to increase the number of nuclear warheads.[6] Thus, the NWS are thoroughly disregarding the NPT provisions.

Apart from disarmament, the unilateral decision by the US and Israel, an NWS and a non-signatory to the NPT, respectively, to attack nuclear facilities in Iran, an NPT member state, has severely damaged the legitimacy of the NPT regime. Iran claimed that it was enriching uranium as per its right[7] under Article IV of the NPT,[8] which talks about “…the inalienable right of all the Parties to the Treaty to develop research, production and use of nuclear energy for peaceful purposes without discrimination…”.[9]

The fate of the Comprehensive Test Ban Treaty (CTBT), which prohibits nuclear testing, hangs in the balance due to President Donald Trump’s announcement of the resumption of nuclear testing in October 2025.[10] Although the treaty has not entered into force due to non-ratification by several states, including the US, China, and Russia’s de-ratification in 2023, the Treaty has been observed by all countries since 1996, except North Korea.

In February 2026, the US Undersecretary of State for Arms Control and International Security Thomas DiNanno, at the UN Conference on Disarmament in Geneva, accused China of conducting a ‘decoupling’ nuclear test on 22 June 2020.[11] Previously, the US State Department’s Compliance Reports of 2020[12] and 2024[13] have raised questions regarding nuclear tests by Russia and China. However, these accusations have not been backed by the CTBT Organisation (CTBTO), which has a network of approximately 300 facilities across the globe to monitor nuclear testing in any part of the world.[14]

Russian President Vladimir Putin has vowed to take “reciprocal measures” should the US go ahead with the nuclear testing.[15] China has refuted the US allegations and called them a pretext to resume nuclear tests.[16] If the US walks the talk on its nuclear rhetoric, then it is likely to have a domino effect, and there is a possibility that other countries may also resume testing.

The last surviving bilateral arms control treaty, New START, expired on 5 February........

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