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 2026, marking the end of an era of arms control. In fact, the weakening of the global arms control architecture began gradually at the start of the 21st century, with the US withdrawal from the Anti-Ballistic Missile (ABM) Treaty in 2002. Subsequently, the US withdrew from the Cooperative Threat Reduction Program, the Intermediate-Range Nuclear Forces (INF) Treaty and the Open Skies Treaty in 2012, 2019 and 2020, respectively.

Putin proposed abiding by the nuclear arms limits of the New START Treaty for one year after its expiration. Still, US President Trump rejected the proposal and wants a new treaty altogether.[17] However, the main casualty of the Treaty’s demise is trust, transparency and predictability.

There are disagreements between the US and Russia on several issues regarding future arms control negotiations. The US advocates for China’s involvement in future negotiations,[18] whereas Russia wants Britain and France included.[19] The US objects to Russia’s tactical nuclear weapons,[20] and the Kremlin’s “novel nuclear missile systems”.[21] Conversely, Russia expresses concerns about the US’s high-precision conventional capabilities[22] and the Pentagon’s missile defence systems.[23]

Moreover, the ongoing Russia–Ukraine war has further diminished trust between the two countries, making it difficult for them to sit at the negotiating table and thrash out a new arms control treaty. Without the New START, there are no limits on the strategic weapons of the leading NWS.

Emerging Nuclear Triangularity

Deterrence was the foundation of the arms control framework between the US and Russia, a system characterised by near parity in numbers and stability. Having interacted for years, they had developed trust and a degree of predictability regarding each other’s behaviour in the nuclear sphere. With China’s expanding nuclear arsenal, a systemic shift is occurring.

According to reports, China’s nuclear weapons have exponentially increased from approximately 200 warheads in 2020 to 600 warheads today.[24] The presence of new missile silos, the development of Multiple Independently Targetable Re-entry Vehicle (MIRV)-based ICBMs, and the production of plutonium all suggest that China is experiencing substantial nuclear expansion. Continuing this trajectory, China will soon reach an arsenal size equivalent to the deployed strategic weapons of the US and Russia, which is around 1500 warheads each.

This might create a structural dilemma between the US, Russia and China. The US might feel threatened by the two peer nuclear powers, which are strategic partners, whereas it has so far had only a single nuclear peer, Russia. The US National Security Strategy (NSS) 2022 states the “need to deter two major nuclear powers, each of whom will field modern and diverse global and regional nuclear forces”.[25] The US National Defence Strategy and the Nuclear Posture Review of 2022 discuss the anticipated “stress on strategic stability” from the “modern and diverse nuclear capabilities” of China and Russia.[26] If the US manufactures warheads equivalent to the combined strength of Russia and China, it will restart the three-way nuclear arms race.

Moreover, China’s nuclear rise is also creating doubts in its neighbourhood, with the ongoing nuclear debates in nuclear-latent-states of the Indo-Pacific, Japan and South Korea. Further, China’s rise as a third nuclear superpower does not inspire confidence, given its questionable record on non-proliferation. It is believed to have transferred nuclear technology to Pakistan, North Korea and Iran. Thus, the shift to the emerging nuclear triangularity is likely to challenge strategic stability in the coming years.

Extended Nuclear Deterrence

The US nuclear umbrella over its allies in Europe and Asia has served as one of the major non-proliferation measures that has dissuaded allies from developing their own nuclear arsenal. However, there have been doubts over the US commitment due to President Trump’s actions in the past few months.

In a blow to transatlantic relations, Trump declared in March 2025 that he would not consider defending the NATO allies if they didn’t pay. He stated, “If they don’t pay, I’m not going to defend them. No, I’m not going to defend them.”[27] More recently, Trump said the US does not “have to be there for NATO”[28], showing his disdain towards the allies. Trump’s erratic remarks and his stance on Greenland[29] have all dented the US’s credibility and its commitments to extend nuclear deterrence to its allies.

As a result, Europe is thinking of having its own nuclear deterrent, without disturbing the NATO nuclear umbrella. In July 2025, France and the UK decided to coordinate their independent nuclear forces more closely under the Northwood Declaration.[30] In another major development in Europe on 2 March 2026, France decided to employ the policy of ‘Forward Deterrence’, under which the European partners will host French aircraft on a nuclear deterrent mission.[31] The partners in this arrangement are Germany, Greece, Poland, the Netherlands, Belgium, Denmark and Sweden. Additionally, in a joint declaration in March 2026, France and Germany have ‘established a high-ranking nuclear steering group’[32] for strategic cooperation. Under the agreement, German conventional forces would participate in French nuclear exercises, and both countries would visit strategic sites in each other’s territory.[33]

Trump’s attitude towards allies and questions about extended nuclear deterrence have also caused a flutter in the Indo-Pacific. Although the majority of Japanese still support the Three Non-Nuclear Principles—not to produce, possess or host nuclear weapons in its territory, there are influential voices that want a review of Japan’s nuclear policy.[34] In South Korea, there is solid public support for developing an independent nuclear deterrent.[35] During President Joseph Biden’s tenure in office, the US lifted restrictions on its missile development, established the Nuclear Consultative Group and launched the Washington Declaration. President Trump has gone a step further and has given a go-ahead for South Korea to build a nuclear-powered submarine, with the US promising to provide nuclear fuel for the propulsion.[36] The Pentagon wants to play a “critical, but more limited” role, placing the primary responsibility for defending the Korean Peninsula on South Korea.[37]

While the US’s extended deterrence guarantees are getting weaker, states possessing nuclear weapons are entering into bilateral mutual defence treaties. President Putin and North Korean leader Kim Jong Un signed the ‘Treaty on Comprehensive Strategic Partnership’ on 19 June 2025, which calls for both countries to assist each other “using all the means it possesses without delay…”.[38] Further, Russia has already stationed some of its tactical nuclear weapons in Belarus.[39]

Saudi Arabia and Pakistan signed a mutual defence pact in September 2025, which states that “any aggression against either country shall be considered an aggression against both”.[40] A senior Saudi official has gone further to suggest that the two countries will “utilise all defensive and military means deemed necessary depending on the specific threat”,[41] not denying a possible nuclear option in a future contingency. Although the treaty’s effectiveness is evident amid the ongoing turmoil in West Asia, it warrants serious consideration.

Erosion of Nuclear Taboo

Tannenwald defines nuclear taboo as “not the act of non-use itself, but the deeply rooted belief that such use is illegitimate”.[42] She dismisses ‘deterrence’ as a reason for non-use of nuclear weapons after 1945. She corroborates her argument by emphasising the non-use of nuclear weapons by the NWS, despite facing strategic setbacks in conflicts with nations having no nuclear weapons and hence no prospect of nuclear retaliation.[43] According to her, the stigmatisation of the use of nuclear weapons was the only reason nuclear weapons have not been used since the nuclear bombing in Hiroshima and Nagasaki.[44]

The rhetoric plays an important role in establishing and sustaining this taboo. Unfortunately, the nuclear taboo is under pressure, particularly in light of nuclear threats issued by leaders worldwide.[45] Such statements “risk normalising the idea of nuclear weapons use and undermining the taboo”.[46] Thus, a secular erosion of the nuclear taboo is going on, and there is a need to reinforce the nuclear taboo.

AI and Nuclear Escalation Risk

The increasing use of AI has a profound impact on nuclear decision-making in multiple ways. The military use of AI helps increase situational awareness, enable rapid data processing, identify targets, simulate battle scenarios, and assess patterns, as seen in the West Asian conflict, though in the conventional domain. However, the AI has many limitations, including automation bias, hallucinations, algorithmic brittleness, and a lack of transparency. It means the AI can produce factually incorrect outputs, and the system may fail if exposed to data different from the data on which it was trained.

While these AI limitations can be overcome in other fields, in the military domain, that too, while using nuclear weapons, is unacceptable, as it may lead to catastrophic consequences. In the event of cyberattacks on the AI, the system’s integrity could be compromised, potentially impacting decision-making at a critical time. Moreover, the AI might “misjudge adversary intentions, heighten threat perceptions and increase nuclear escalation risk”.[47]

The use of AI in reconnaissance systems, such as satellites, makes it difficult to maintain the confidentiality of nuclear weapons locations.[48] This could challenge the state’s second-strike capability and motivate it to launch a first strike, thereby undermining strategic stability. Though the NWS have stated that they have, and will continue to have, human oversight of nuclear launch decisions, this may not be adequate. In an age of AI, humans will need to make decisions with AI-driven decision support systems (DSS), often under intense stress, thereby increasing the risk of misperception and overreaction. Thus, AI is likely to introduce greater uncertainty into the already fragile global nuclear order.

What It Means for India

India has consistently advocated for a global non-proliferation and disarmament regime that is non-discriminatory. Even in the Eighteen Nations Disarmament Committee (ENDC) negotiations at the UN between 1962 and 1969, which produced the NPT in 1968, India argued against both vertical and horizontal non-proliferation. The country did not accept the treaty, calling it ‘nuclear apartheid’ because it did not stop vertical proliferation and was focused only on horizontal proliferation, creating nuclear haves and have-nots. Similarly, India did not sign the CTBT.

Despite being outside the NPT, India’s record in the non-proliferation domain is clean and unblemished compared with other nuclear-armed states. Similarly, India has announced a voluntary moratorium on nuclear testing, without signing the CTBT. Due to its clean record, India received an NSG waiver in 2008 and is part of the Global Export Control Regimes.

An examination of the ongoing conflicts involving nuclear-armed states indicates that these conflicts are being fought at the conventional level and have not escalated to nuclear warfare. Even in the case of the India–Pakistan conflict, India could call out Pakistan’s nuclear bluff by fighting the war under nuclear overhang. Therefore, the nuclear deterrent has served New Delhi well.

The global nuclear order is gradually unravelling. NPT is going through a credibility crisis. The future of CTBT hangs in the balance. With the last surviving bilateral arms control treaty dead and no possibility of a new treaty in the near future, the global nuclear regime has been considerably weakened. The emerging nuclear triangularity is likely to create a structural dilemma that, if left unmanaged, could lead to an arms race. The traditional extended deterrence provided by the US is collapsing, and new equations are rising. 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 is likely to affect strategic stability by compressing decision-making timelines, increasing the risk of miscalculation during crises, and producing opaque recommendations.

[1] Kjølv Egeland, “The Ideology of Nuclear Order”, New Political Science, Vol. 43, No. 2, 2021, p. 208.

[2] William Walker, “Nuclear Order and Disorder”, International Affairs, Vol. 76, No. 4, October 2000, p. 703.

[3] Steven E. Miller and Alexey Arbatov, “The Rise and Decline of Global Nuclear Order?”, American Academy of Arts & Sciences.

[4] “Treaty on the Non-Proliferation of Nuclear Weapons”, United Nations Office of Disarmament Affairs.

[5] “Nuclear Risks Grow as New Arms Race Looms”, Stockholm International Peace Research Institute (SIPRI), 16 June 2025.

[6] “President Delivers Speech on France’s Nuclear Deterrence”, French Embassy in UK, 4 March 2026.

[7] “Iran Reaffirms Right to Enrich Uranium Ahead of Key Talks in Turkiye”, Al Jazeera, 24 July 2025; “Kazem Gharibabadi Issued a Statement in Response to the Director General of the International Atomic Energy Agency’s (IAEA) Report Concerning Iran”, Ministry of Foreign Affairs, Islamic Republic of Iran, 1 June 2025.

[8] “Statement by H.E. Mr. Seyed Abbas ARAGHCHI Minister of Foreign Affairs of the Islamic Republic of Iran Before the Plenary Meeting of the Conference on Disarmament”, Ministry of Foreign Affairs, Islamic Republic of Iran, 17 February 2026.

[9] “The Treaty on the Non-Proliferation of Nuclear Weapons”, Department for Disarmament Affairs, United Nations.

[10] “The Official Truth Social Account of Donald Trump”, Truth Social, 30 October 2025.

[11] “United States Statement by Under Secretary of State for Arms Control and International Security by  Thomas DiNanno”, US Mission to International Organisations in Geneva, 6 February 2026.

[12] “2020 Adherence to and Compliance with Arms Control, Nonproliferation, and Disarmament Agreements and Commitments (Compliance Report)”, The US State Department, June 2020.

[13] “Adherence To and Compliance with Arms Control, Nonproliferation, and Disarmament Agreements and Commitments”, The US State Department, April 2024.

[14] “Statement by Robert Floyd, Executive Secretary of the CTBTO”, Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organisation, 30 October 2025.

[15] Alastair McCready, “Putin Says Russia to Take ‘Reciprocal Measures’ if US Resumes Nuclear Tests”, Al Jazeera, 6 November 2025.

[16] “China Urges U.S. to Stop Seeking Pretexts for Resuming Nuclear Tests”, Xinhua, 25 February 2026.

[17] “The Official Truth Social Account of Donald Trump”, Truth Social, 6 February 2026.

[18] Daniel Bush, “Trump’s Nuclear Arms Control Push with Russia Hinges on China”, BBC, 6 February 2026.

[19] “Kremlin Says British and French Arsenals Must Ultimately be Part of Nuclear Disarmament Talks”, Reuters, 29 September 2025.

[20] “United States Statement by Under Secretary of State for Arms Control and International Security by  Thomas DiNanno”, no. 11.

[22] “Joint Statement by the People’s Republic of China and the Russian Federation on Global Strategic Stability”, Ministry of Foreign Affairs, People’s Republic of China, 9 May 2025.

[23] “Statement of the Ministry of Foreign Affairs of Russia Concerning the Expiration of the Russia-US New START Treaty”, The Ministry of Foreign Affairs of Russian Federation, 4 February 2026.

[24] “Nuclear Risks Grow as New Arms Race Looms”, no. 5.

[25] “The US National Security Strategy”, The White House, October 2022, p. 21.

[26] “The US National Defence Strategy and Nuclear Posture Review”, US Department of Defense, October 2022, p. 4.

[27] “Trump Casts Doubt on Willingness to Defend Nato Allies ‘if they don’t pay’”, The Guardian, 7 March 2025.

[28] “We Don’t Have To Be There For NATO”: Trump Slams Allies Over Iran War”, NDTV, 28 March 2026; Phil Stewart, “Pentagon Declines to Reaffirm NATO’s Collective Defence, Says Up to Trump”, Reuters, 31 March 2026.

[29] James FitzGerald, “Why Does Trump Want Greenland and What Could It Mean for Nato and the EU?”, BBC, 22 January 2026.

[30] Elizabeth Pineau, “France, Britain Unveil Nuclear Weapons Cooperation to Counter Threat to Europe”, Reuters, 11 July 2025.

[31] “President Delivers Speech on France’s Nuclear Deterrence”, no. 6.

[32] “Joint Declaration of President Macron and Chancellor Merz”, Official Website of President of France, 2 March 2026.

[34] Tim Kelly, John Geddie, Ju-min Park, Joyce Lee, Josh Smith and David Lague, “Trump Shock Spurs Japan to Think About the Unthinkable: Nuclear Arms”, The Japan Times, 20 August 2025; Rieko Miki and Junnosuke Kobara, “Is it Time for Japan to Have Nuclear Arms? Trump Uncertainty Sparks Debate”, Nikkei Asia, 30 April 2025; Sakura Murakami, “Japan Should Have Nuclear Weapons, Official Reportedly Says”, The Japan Times, 19 December 2025.

[35] “Trump Shock Pushes Japan Toward Rethinking Nuclear Taboo”, Politics Today, 20 August 2025.

[36] Ju-min Park and Joyce Lee, “South Korea Seeks US Fuel for Domestically Built Nuclear-powered Submarine, Official Says”, Reuters, 7 November 2025; Josh Smith, David Brunnstrom and Costas Pitas, “Trump Says South Korea Has Approval to Build Nuclear-powered Submarine”, Reuters, 30 October 2025.

[37] Yonhap, “New US Defence Strategy Highlights Seoul’s ‘Leading Role’ in Peninsula Security: Ministry”, The Korea Times, 26 January 2026.

[38] “DPRK-Russia Treaty on Comprehensive Strategic Partnership, 2024.6.19”, DPRK Notes, 20 June 2024.

[39] “Russian Weapons Transfer Said Complete”, Arms Control Today, January/February 2024.

[40] Munir Ahmed and Jon Gambrell, “Saudi Arabia Signs a Mutual Defence Pact with Nuclear-armed Pakistan After Israel’s Attack on Qatar”, Associated Press, 18 September 2025.

[41] Andrew England, Ahmed Al Omran and Humza Jilani, “Saudi Arabia Signs ‘Strategic Mutual Defence’ Pact with Pakistan”, Financial Times, 18 September 2025.

[42] Shafia Batool, “The Gradual Erosion of the Nuclear Taboo”, Wavell Room, 17 September 2025.

[43] Nina Tannenwald, The Nuclear Taboo: The United States and the Non-Use of Nuclear Weapons Since 1945, Cambridge University Press, 2007.

[45] Ali Vitali, “Trump Vows North Korea Threat Will Be Met With ‘Fire and Fury’”, NBC News, 9 August 2017; Stephen Blank, “Vladimir Putin’s Endless Nuclear Threats are a Sign of Russian Weakness”, Atlantic Council, 6 November 2025.

[46] “International Norms, Nuclear Taboo, and the Risk of Use of Nuclear Weapons”, Vienna Centre for Disarmament and Non-Proliferation, 31 March 2023.

[47] Vladislav Chernavskikh and Jules Palayer, “Impact of Military Artificial Intelligence on Nuclear Escalation Risk”, Stockholm International Peace Research Institute (SIPRI), June 2025.

[48] “How Does the Use of AI Make It More Likely Nuclear Weapons Would be Used?”, The International Campaign to Abolish Nuclear Weapons (ICAN), revised in February 2026.

© IDSA