After weeks of tough negotiations and debate, representatives of some 190 governments to the pivotal 11th nuclear Nonproliferation Treaty (NPT) Review Conference failed to reach consensus on a modest outcome document that reaffirms consensus-based commitments made at the 1995, 2000, and 2010 Review Conferences, apparently due to references to Iran’s nuclear program that the United States insisted on including in the document.

Due to intransigence from the five nuclear-armed states, representatives also failed to adopt meaningful new steps in the draft document to advance the treaty’s core goals, particularly on nuclear disarmament, according to experts with the Arms Control Association who attended the month-long conference at UN headquarters in New York.

The NPT Review Conference is held every five years. The last two NPT Review Conferences (2015 and 2022) also failed to produce a consensus outcome document.

The 2026 NPT Review Conference was led by Vietnam’s Ambassador to the UN, Do Hung Viet. Before the 2026 Conference opened, President Du Hong Viet told Arms Control Today that another failure would further weaken the NPT. “We may lose the credibility of the NPT itself,” Viet warned.

“Tragically,  NPT states missed an important opportunity to formally reaffirm their support for the treaty and its core principles, goals, and objectives at a time of increasing nuclear dangers,” said Daryl Kimball, executive director of the Arms Control Association, who has attended and participated as a nongovernmental expert in seven NPT Review Conferences going back to 1995.

“In reality, the ongoing dispute over Iran’s sensitive nuclear activities, which has been complicated by President Trump’s withdrawal from the JCPOA in 2018, cannot be resolved at the NPT Review Conference and must be addressed through serious and more sustained diplomacy outside the halls of the UN,” he continued.

“The draft outcome document, which addresses the status of implementation and compliance with the treaty and next steps relating to each of the NPT’s three main components — nuclear disarmament, nonproliferation, and peaceful uses of nuclear energy under effective safeguards against military diversion — would have formally succeeded in reaffirming states parties’ core commitments and obligations,” Kimball noted.

“Even if the consensus could have been achieved,” Kimball added, “states-parties missed a chance to use the conference to address the dizzying array of nuclear dangers, including the deficit in nuclear disarmament diplomacy.”

For the first time since 1972, there are no agreed limits on the size of the Russian and U.S. nuclear arsenals, the world’s largest. The U.S. government has called for multilateral “strategic stability” talks, but there are no negotiations between Washington and Moscow or with other nuclear-armed states to limit or reduce their arsenals. Without new bilateral or multilateral constraints, there is a serious risk of a dangerous, global nuclear buildup in the years ahead.

“Due to the combined efforts of the NPT’s nuclear five who used aggressive diplomatic intimidation tactics against non-nuclear weapon states, the document failed to call for concrete action steps that are urgently needed to avert a new nuclear arms race and reassure non-nuclear weapon states they will not be attacked by nuclear-armed states,” Kimball charged.

For example, paragraph four of the outcome document fails to call upon the five nuclear-armed states to “negotiate” on “disarmament” with “urgency.” Article VI of the NPT already states they must “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.”

Instead, the draft outcome document pursues “constructive dialogue on the basis of mutual respect and acknowledgement of each other’s security interests and concerns, to ease international tension, promote international peace and stability, enhance confidence and reduce strategic risks, and note that such engagement could facilitate future arms control discussions, and help progress towards nuclear disarmament ….”

“The failure of nuclear weapon states-parties to agree on language that already exists within the Treaty, and the failure to commit to new steps with any urgency, reveals just how wide the disarmament deficit has grown,” emphasised Libby Flatoff, Program and Policy Associate of the Arms Control Association, who also attended the Review Conference.

“One bright spot,” Kimball said, “is that states parties insisted, despite opposition from the U.S. delegation, on including meaningful language in paragraph eight of the draft outcome document in support of the 1996 Comprehensive Test Ban Treaty (CTBT), against the resumption of nuclear testing by any state and the international monitoring and verification system of the Comprehensive Test Ban Treaty Organisation.”

“The draft final outcome document that was worked out over nearly a month of debate and negotiation tells us as much about what some states, particularly the nuclear weapon states, cannot agree upon as much as it tells us what they still do agree upon,” said Kimball.

When reflecting on how the conference was run, Kimball said: “Amb. Viet smartly pursued agreement on a draft outcome document that was relatively short. It focused on principles rather than invoking the names of countries, and it also side-stepped a number of key issues, including the North Korean nuclear challenge, attacks on Ukrainian and Iranian nuclear facilities, and the growing discomfort with the extended nuclear deterrence practices of U.S. allies, in order to try to achieve consensus on core issues. Nevertheless, that was still not enough to achieve agreement among the treaty’s many states and their divergent views.”

“U.S. leadership, always critical to a successful and meaningful NPT process, was sorely lacking,” he said.

“The foundations of the NPT, the cornerstone of global efforts to reduce and eliminate the world’s greatest danger, are cracking due to inattention, intransigence, and ineptitude. Much more enlightened, engaged, and pragmatic leadership from Washington and the capitals of the other nuclear-armed states will be needed to strengthen the system to guard against the growing risks of nuclear arms racing, nuclear testing, and nuclear proliferation,” Kimball said.