For more than half a century, the nuclear nonproliferation regime has rested on a relatively stable bargain. Countries without nuclear weapons agreed not to acquire them. Nuclear-armed nations pledged to pursue disarmament. International inspectors verified compliance, while periodic review conferences allowed governments to adjust the regime as strategic conditions changed.
The institutions remain. The bargain has become much harder to sustain.
The 2026 Review Conference of the Treaty on the Nonproliferation of Nuclear Weapons ended without consensus for the third consecutive review cycle. Governments clashed over Iran, disarmament obligations, regional conflicts and the future of deterrence. They also struggled to incorporate questions that barely existed when the treaty entered into force in 1970: artificial intelligence, military automation and the interaction between conventional and nuclear systems.
Vietnam’s U.N. ambassador, Do Hung Viet, who served as conference president, said delegates had engaged in “honest reflection on the current situation” but could not overcome their differences.
“And in the meantime, a nuclear arms race is, I guess, on the horizon,” Viet said. “We are seeing the modernization of nuclear arsenals, we are seeing the quantitative increase in some nuclear arsenals as well.”
Izumi Nakamitsu, the U.N. high representative for disarmament affairs, warned that confidence was eroding in the treaty and its Article VI, which legally binds all member nations to pursue good-faith negotiations to halt the nuclear arms race and achieve complete nuclear disarmament.
“Non-proliferation and disarmament are two sides of the same coin,” she said. “It is simply wrong for nuclear weapon states to assume that nonproliferation obligations will just be adhered to without nuclear weapon states’ commitment and implementation of disarmament commitment under Article VI.”
The NPT was built around an enduring bargain: prevent the spread of nuclear weapons while gradually reducing those that already exist. The principle remains the same even as the strategic environment changes.
Nuclear competition is no longer defined primarily by two superpowers, familiar delivery systems and bilateral arms control agreements. China is expanding its arsenal. North Korea is a nuclear-armed nation outside the treaty. Iran is a focus of disputes over enrichment and verification. Cyber operations, hypersonic weapons, autonomous systems and artificial intelligence affect deterrence, warning systems and the speed at which political leaders may have to make irreversible decisions.
The pressure forces governments to ask whether the assumptions that once made it workable still describe the world the treaty is expected to govern. The same question confronts the United Nations Security Council.
Its founding bargain was explicit. The victorious powers of the Second World War received permanent seats and veto authority because their participation was considered indispensable to maintaining international peace. The structure privileged agreement among the major powers over equal representation among member nations.
More than 80 years later, the Council still gives permanent seats to China, France, Russia, the United Kingdom and the United States. Ten rotating seats are shared among every other country. Africa and Latin America lack permanent representation.
At the Africa Forward summit in Nairobi, African leaders again called for a Council that better reflects contemporary demographics and political realities. French President Emmanuel Macron, whose country holds a permanent seat, supported stronger African representation and renewed calls for permanent members to refrain from using the veto in cases involving genocide, crimes against humanity and large-scale war crimes.
U.N. Secretary-General António Guterres argued that the imbalance now affects more than representation.
“The Security Council that today does not represent the geographical realities of the world — with three European permanent members, one North American and one Asian, and no African and no Latin American — is obviously a Security Council that has a problem of legitimacy,” he said. “And that brings with it a problem of effectiveness.”
The Council’s mandate has not changed. Nor has the underlying principle that major powers must participate in any credible collective security system. What has changed is the distribution of political, economic and demographic power beyond the countries that designed the institution in 1945.
That creates a paradox. The founding bargain preserves the Council’s authority while making meaningful reform extraordinarily difficult, because the countries whose privileges would change have the power to block those changes.
The office of the secretary-general illustrates another version of the same pressure.
For much of the United Nations’ history, the role centered on diplomacy among governments, conflict mediation, humanitarian coordination and management of the international civil service. Those responsibilities remain but many of the problems now confronting the organization emerge from scientific and technological change rather than traditional international politics.
Climate change, AI, biotechnology, quantum technologies, cybersecurity, pandemic preparedness and space governance blur the traditional boundary between technical expertise and political diplomacy.
Former U.N. Geneva Director-General Michael Møller argued that the next secretary-general will need to do more than manage today’s crises.
“You need a leader who has a very clear vision of what the future might be or what it takes to harness the system and to reform the system in such a way that for the next 20, 30, 40 years we are going to come with a structure that is actually going to help ensure that humanity has a grip on that future,” he said.
The International Science Council has made a similar argument, urging the United Nations to make scientific knowledge a permanent component of multilateral governance rather than an occasional input into political negotiations. The pressure is institutional. A position created to manage relations among governments is expected to guide decisions about scientific and technological systems that cross borders and traditional diplomatic mandates.
Climate change puts comparable pressure on international law.
For decades, governments addressed global warming mainly through political negotiations, national commitments and specialized climate agreements. In 2026, however, the U.N. General Assembly overwhelmingly endorsed an advisory opinion of the International Court of Justice concluding that nations’ existing obligations under international law extend to protecting the climate system.
The Assembly welcomed the opinion as “an authoritative contribution to the clarification of existing international law” and urged governments to comply with those obligations.
Led by Vanuatu and other vulnerable island nations, the initiative sought to frame climate change as an environmental and economic challenge and a question of legal responsibility. The court concluded that failure to take appropriate action could constitute an internationally wrongful act and that countries harmed by climate change could, under some circumstances, be entitled to reparations.
Supporters argued that established principles of state responsibility, human rights and environmental protection already provided the necessary legal foundation. Opponents argued that the court and the General Assembly were extending obligations beyond those governments had explicitly accepted.
The disagreement reflects a broader question confronting many international institutions. One side views reinterpretation as necessary if longstanding principles are to remain meaningful under new conditions. The other sees the same process as expanding institutional authority without renewed political consent.
Pressure falls not only on rules but on the bargains that gave those rules legitimacy. The NPT must respond to technologies and strategic relationships that did not exist in 1970. The Security Council must justify a distribution of authority inherited from 1945. The secretary-general’s office must integrate scientific expertise into a role conceived around traditional diplomacy. International courts must decide whether longstanding legal principles apply to planetary challenges their authors never contemplated.
Institutions survive pressure by persuading governments that their original charters are still capable of organizing cooperation in a very different world.