The Nuclear Non-Proliferation Regime in Danger

Three weeks before the start of Operation Epic Fury, a significant event for international security went almost unnoticed. The New START, the last existing agreement for the limitation and reduction of strategic nuclear weapons between the United States and Russia, expired without either party pushing for its renewal. As a result, the two main nuclear powers in the world found themselves— for the first time since 1972— without formal limits or mechanisms for data exchange, inspection, and mutual verification of their strategic arsenals. This signal is concerning, considering that both countries hold nearly 90% of the world’s 12,241 nuclear warheads.[1].

The year 2026 has been particularly critical for efforts to prevent and contain nuclear proliferation. The attacks by the United States and Israel against Iran, President Trump’s questioning of NATO, and interstate tensions in East Asia have weakened what is known as the nuclear taboo[2], reinstating interest in nuclear weapons as a means of self-protection.

In this context, the XI Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) begins this week in New York[3]. Convened every five years, this forum brings together the 191 States Parties to assess compliance with the three pillars of the treaty: non-proliferation, disarmament, and the peaceful use of nuclear energy. It is also the only multilateral forum where nuclear powers must account to the rest of the world for their commitments in this area.

The background, however, is not encouraging. The conferences of 2005, 2015, and 2022 failed to produce a consensus document, while the deterioration of the strategic environment erodes the political foundations of the regime. In an increasingly tense global scenario, the fundamental question regarding the conference is not whether the NPT can continue to produce multilateral consensus, but rather, how robust that capacity remains in a radically different environment from that which gave rise to it.

2. The NPT: A Cornerstone Under Tension

The NPT (signed in 1968) is the most ratified arms control and disarmament agreement in history. With 191 signatories, its relevance lies in achieving that States voluntarily— and in a legally binding manner— renounce a capacity for mass destruction, placing collective security above individual deterrence. Its performance, so far, has been positive. In the 1960s, several projections anticipated that by the end of the 20th century there could be as many as 20 or 25 nuclear powers[4], yet today only nine States acknowledge or have a history of possessing such weaponry (Figure 1). Furthermore, the NPT constitutes the central axis of the nuclear non-proliferation architecture, around which other complementary instruments are articulated, such as the monitoring mechanisms of the International Atomic Energy Agency (IAEA), nuclear-weapon-free zones, and nuclear test ban treaties.

Regarding the regulatory framework, the NPT rests on a foundational distinction between States recognized as having the right to be nuclear-armed (the United States, Russia, the United Kingdom, France, and China) and those that do not. Based on this asymmetry, the agreement organizes three pillars. The first is the containment of proliferation. Nuclear-armed States commit not to transfer them or assist in their development, while others renounce acquiring them. The second is disarmament: Article VI obliges all States Parties to negotiate in good faith measures aimed at halting the arms race and achieving nuclear disarmament. The third is the peaceful use of nuclear energy. In this regard, Article IV recognizes the right of all States to develop this technology for civilian purposes.

Figure 1. Global Nuclear Weapons Inventories, January 2025.

However, the historical success of the NPT coexists with a structural tension. By institutionalizing a military hierarchy between “nuclear-rich” and “nuclear-poor” States, the Treaty has consolidated a persistent inequality, where the latter maintain their renunciation, while the former have preserved their arsenals and continue to modernize them, not only in number but also qualitatively[5]. This has generated increasing questions about compliance with the disarmament promise contained in Article VI, which has contributed to eroding the legitimacy of the multilateral regime.

3. An Exceptionally Adverse International Environment

The XI Review Conference of the NPT takes place in one of the most challenging contexts since the end of the Cold War. Four elements shape this picture of systemic fragility for 2026 (Figure 2).

The first element is the collapse of the last bilateral nuclear control framework between the two main powers. Beyond its formal expiration in February 2026, the New START had already ceased to operate in practice since 2023, when Russia suspended its participation, inspections ceased, and data exchange was interrupted. Of course, the formal loss of that regime eliminates transparency and predictability between Washington and Moscow, but, more importantly, it reinforces among non-nuclear-armed States the perception that the obligation to negotiate in good faith for disarmament is no longer a priority. The problem is greater when considering that both powers maintain active qualitative enhancement programs for their arsenals (known as vertical proliferation). The United States, with the LGM-35A Sentinel, the Columbia-class submarine, and the B-21 Raider bomber; and Russia, with the Sarmat, the Yars, the Avangard hypersonic system, and new intercontinental ballistic missiles (ICBMs)[6].

Figure 2. Recent Challenges to the Nuclear Non-Proliferation Regime, 2022-2026.

This absence of nuclear control between the United States and Russia also coincides with a more permissive environment regarding the logic of deterrence. China, for its part, increased its arsenal from approximately 500 warheads in January 2024 to nearly 600 in January 2025. Additionally, it is building new missile silo fields and expanding its underwater and aerial capabilities with an ambitious horizon for 2030. North Korea, on the other hand, continued its ballistic testing and in November 2024 tested the Hwasong-19, a new solid-fuel missile, while Kim Jong-un called for an “unlimited” expansion of the nuclear program. Meanwhile, in Europe, Trump’s criticisms of NATO reopened the debate on security guarantees, while the Northwood Declaration (2025) reaffirmed the strategic value of nuclear deterrence through a bilateral framework between two nuclear powers: the United Kingdom and France.

The Iranian crisis adds a different but equally corrosive pressure. The attacks by the United States and Israel against Iranian nuclear infrastructure—in June 2025 and then in February 2026—have brought back to the forefront the most delicate ambiguity of the treaty: how to distinguish between peaceful use and latent proliferation, and what mechanism the regime has to manage that boundary when diplomatic dialogue collapses and military force replaces it. Before the attacks, Iran had accumulated 440.9 kg of uranium enriched to 60%, well above the 3.67% allowed under the 2015 Joint Comprehensive Plan of Action. Following the attacks, the IAEA lost continuity of knowledge regarding Iranian inventories due to the suspension of inspections. Nevertheless, Iran remains a part of the NPT, but the safeguards regime has been suspended, which serves as a reminder that nuclear verification ultimately depends on the political will of the monitored States. 

Finally, this picture is overshadowed by the recent history of the review process itself. Of the last four review conferences, only the one in 2010 achieved a final consensus document, while those in 2005, 2015, and 2022 did not reach that goal. A new failure in New York would not imply the immediate legal collapse of the NPT, as its validity does not formally depend on the success of these meetings. However, it would deepen a more subtle and, for that reason, more dangerous deterioration, such as the erosion of its normative capacity[7]. The NPT is the institutional knot upon which a broader architecture depends, so a third consecutive conference without agreement would reinforce the perception that the regime can no longer reaffirm its own rules or enforce its commitments against its most powerful members.    

4. Implications for Latin America and Chile

It is precisely from this potential loss of credibility of the NPT that the implications of the current scenario for Latin America and countries like Chile must be understood. Although the region does not face an immediate nuclear threat in terms of armaments, it does depend on the stability of the non-proliferation regime for strategic, economic, and institutional reasons. When the global nuclear architecture weakens, its effects do not stop at the powers, as they also reach medium and small States, which rely on norms, verifications, and multilateral arrangements to reduce their vulnerability.

In the case of Chile, there is also a consistent track record of commitment to the non-proliferation regime (Figure 3). Beyond formal adherence to its central instruments, Chile has actively participated in the verification mechanisms of the Comprehensive Nuclear-Test-Ban Treaty and ratified the Treaty on the Prohibition of Nuclear Weapons in 2021, reaffirming its value as a complement—and not a substitute—for the NPT. This position places Chile among the non-nuclear-armed States that press for effective content to be given to Article VI, convinced that the legitimacy of the regime ultimately depends on disarmament ceasing to be a deferred promise.

Figure 3: Chile and the Central Instruments of the Non-Proliferation Regime

But Chile’s interest in preventing and containing proliferation goes beyond the normative. It is also material. The deterioration of the regime increases the risk that States in crisis, or non-state actors, gain access to nuclear or radioactive materials; a scenario particularly sensitive for regions with limited prevention and response capabilities. Similarly, a nuclear escalation in Europe, the Middle East, or the Korean Peninsula would have immediate effects on energy markets, commodities , and global finance. For an economy highly dependent on foreign trade like Chile’s, these external shocks would not be abstract: they would affect prices, logistical chains, energy costs, and margins of macroeconomic stability.

From this perspective, the conference in New York matters more than it may initially seem. For the international community, this meeting constitutes a test of whether the rules-based international order retains its influence or rather shifts toward a logic of national interest. For Chile, preserving the NPT and the architecture surrounding it is more than an exercise in abstract adherence to international law. It is a way to safeguard a strategic environment in which medium States can still rely on rules rather than on their own deterrent capabilities.

Diego Sazo
Head of the International Relations Research Area at AthenaLab.

Camila Hernández
Co-founder of the Center for Non-Proliferation Studies (CNP Chile) and WIIS Chile, the network of women in international security

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[1] Stockholm International Peace Research Institute, Summary of the SIPRI Yearbook 2025: Armaments, Disarmament and International Security (Oxford: Oxford University Press, 2025).

[2] James M. Acton, “Is the Nuclear Taboo Eroding?,” Carnegie Endowment for International Peace, 2023; and Nina Tannenwald, “The Bomb in the Background: What the War in Ukraine Has Revealed About Nuclear Weapons,” Foreign Affairs, February 24, 2023.

[3] The meeting takes place from April 27 to May 22, 2026.

[4] Arms Control Association, “Timeline of the Nuclear Nonproliferation Treaty (NPT),” Arms Control Association, last reviewed in May 2025.

[5] Hans M. Kristensen and Matt Korda, “World Nuclear Forces,” in SIPRI Yearbook 2024: Armaments, Disarmament and International Security (Oxford: Oxford University Press, 2024), 272–367.

[6] Hans M. Kristensen and Matt Korda, “World Nuclear Forces,” in SIPRI Yearbook 2025: Armaments, Disarmament and International Security (Oxford: Oxford University Press, 2025), 178-202.

[7] Alexander Wendt, Social Theory of International Politics (Cambridge: Cambridge University Press, 1999) and Martha Finnemore and Kathryn Sikkink, “International Norm Dynamics and Political Change,” International Organization 52, no. 4 (1998): 887-917.