From Hiroshima to September 26: The long road to nuclear disarmament
Every September 26, the world marks the International Day for the Total Elimination of Nuclear Weapons — a day that carries a question dating back to the earliest years of the nuclear age: can a world that created weapons capable of destroying entire cities ultimately find a way to eliminate them?
The date was formally designated by the United Nations General Assembly in December 2013, following the first-ever high-level meeting of the General Assembly on nuclear disarmament held on September 26 that year. The observance has been held annually since 2014, with the UN using the day to promote awareness of the dangers posed by nuclear weapons and the objective of their complete elimination.
But the history behind September 26 reaches much further back — to the closing months of World War II, the destruction of Hiroshima and Nagasaki, the Cold War arms race, repeated efforts to control nuclear weapons and a decades-long divide between nuclear-armed and non-nuclear states.
The beginning of the nuclear age
In August 1945, the United States used atomic bombs against Hiroshima and Nagasaki in Japan. According to the United Nations, the two bombings destroyed the cities and were estimated to have killed about 213,000 people immediately. The attacks demonstrated, on an unprecedented scale, the destructive power of nuclear weapons.
The consequences of the bombings also transformed international thinking about warfare. The possibility that nuclear technology could be developed for military purposes meant that the control of atomic energy could no longer be treated simply as a national matter.
The United Nations, created in 1945 with the stated objective of maintaining international peace and security, confronted the issue almost immediately.
In 1946, the General Assembly adopted its first resolution. Among its objectives was the creation of an international system for controlling atomic energy and eliminating atomic weapons and other major weapons capable of mass destruction. The UN’s Atomic Energy Commission was established to make proposals towards that objective, although it was eventually dissolved in 1952 without achieving the intended international agreement.
Thus, nuclear disarmament was not an issue added to the UN agenda decades later. It was present almost from the organisation’s beginning.
The Cold War and the arms race
Instead of disappearing after World War II, nuclear weapons became central to the emerging rivalry between the United States and the Soviet Union.
The Soviet Union developed its own atomic bomb, and the two superpowers entered an arms race that produced increasingly sophisticated and destructive nuclear arsenals. Nuclear weapons became intertwined with military strategy and national security.
The danger became particularly visible during the Cuban Missile Crisis of 1962, when the United States and Soviet Union confronted each other over Soviet missiles stationed in Cuba.
The crisis produced a new urgency around arms control. A year later, the United States, Soviet Union and United Kingdom concluded the Partial Test Ban Treaty. Opened for signature in 1963, the treaty prohibited nuclear test explosions in the atmosphere, outer space and underwater, although underground testing remained outside its prohibition. The UN describes the Cuban Missile Crisis as giving renewed urgency to the negotiations that produced the treaty.
The agreement did not eliminate nuclear weapons, but it represented an important shift: nuclear powers were beginning to accept that rules limiting aspects of the arms race were necessary.
The Nuclear Non-Proliferation Treaty
The next major step came with the Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the NPT.
The treaty was opened for signature in 1968 and entered into force in 1970. It became the central framework of the international nuclear non-proliferation regime. According to the UN, 191 states are parties to the treaty, including the five states recognised under the treaty as nuclear-weapon states.
The NPT was designed around three broad areas: preventing the spread of nuclear weapons, promoting peaceful uses of nuclear energy and pursuing nuclear disarmament.
Its history also reveals one of the enduring difficulties of the nuclear order. The treaty created different categories of states based on whether they had manufactured and exploded a nuclear weapon before January 1, 1967. The five states recognised as nuclear-weapon states under the treaty are China, France, Russia, the United Kingdom and the United States.
India did not join the NPT, maintaining that the treaty was discriminatory because it created different obligations for nuclear-weapon and non-nuclear-weapon states.
India’s early call for nuclear disarmament
India’s nuclear history adds another important dimension to the story.
Long before India conducted a nuclear test, it advocated the elimination of nuclear weapons.
According to the Ministry of External Affairs, India called in 1948 for limiting atomic energy to peaceful purposes and eliminating atomic weapons from national armaments. In 1954, India became the first country to call for a ban on nuclear testing. It subsequently supported initiatives connected with the Partial Test Ban Treaty and called for international negotiations on nuclear non-proliferation.
India’s position continued to develop through the Cold War
In 1978, it proposed negotiations for an international convention prohibiting the use or threat of use of nuclear weapons. In 1982, India called for a “nuclear freeze” covering the production of fissile material for weapons, nuclear weapons and related delivery systems.
One of India’s most significant disarmament proposals came in 1988, when Prime Minister Rajiv Gandhi presented an Action Plan for Ushering in a Nuclear-weapon Free and Non-Violent World Order at the UN.
The plan proposed the elimination of all nuclear weapons in stages and emphasised that nuclear disarmament should be global, universal and non-discriminatory. It called for all nuclear-weapon states to participate and argued that progress towards disarmament should be accompanied by changes in military doctrines, policies and institutions.
Yet India’s own security calculations eventually led it to retain the nuclear option.
Pokhran and India’s nuclear transition
India conducted its first nuclear test at Pokhran, Rajasthan, in May 1974.
The test had major international consequences. The Nuclear Suppliers Group was subsequently created to control the international transfer of nuclear materials and technology. India, meanwhile, continued developing an indigenous nuclear programme.
For more than two decades, India did not conduct another nuclear test.
That changed in May 1998, when India conducted five nuclear tests at Pokhran and announced that it had acquired nuclear weapons capability. The Indian government’s historical account describes the decision in terms of strategic and national-security considerations, particularly the nuclear environment in India’s neighbourhood.
Following the 1998 tests, India announced a voluntary moratorium on further nuclear testing and articulated a nuclear doctrine centred on credible minimum deterrence and a no-first-use policy.
The developments underscored a central contradiction in the global nuclear debate: states may support the eventual elimination of nuclear weapons while simultaneously arguing that nuclear capabilities are necessary for their security until a universally accepted disarmament framework exists.
The world moves towards nuclear-free zones
The search for alternatives to nuclear arms competition also produced nuclear-weapon-free zones.
The Treaty of Tlatelolco, negotiated by Latin American governments after the Cuban Missile Crisis, established the first nuclear-weapon-free zone in a populated region in 1967.
The South Pacific followed with the Treaty of Rarotonga in 1985. Southeast Asia became another nuclear-weapon-free zone through the Bangkok Treaty, while Africa adopted the Pelindaba Treaty. Central Asia later established its own nuclear-weapon-free zone.
These agreements demonstrated that disarmament did not necessarily have to begin with the nuclear powers themselves. Groups of countries could also establish regional commitments not to develop, acquire or station nuclear weapons.
There were also examples of countries giving up nuclear weapons programmes or inherited arsenals.
South Africa voluntarily abandoned its nuclear weapons programme in 1991. After the dissolution of the Soviet Union, Belarus, Kazakhstan and Ukraine also relinquished nuclear weapons that had been located on their territories, under arrangements connected with the START process.
The push for complete elimination
The end of the Cold War reduced the enormous arsenals accumulated by the United States and Soviet Union, but it did not end the nuclear weapons system.
The UN continued to place nuclear disarmament at the centre of its disarmament agenda.
In 1996, the Comprehensive Nuclear-Test-Ban Treaty was opened for signature. In 2000, the NPT Review Conference adopted 13 practical steps towards systematic and progressive nuclear disarmament. In 2010, NPT states adopted a 64-point action plan covering nuclear disarmament, non-proliferation and peaceful uses of nuclear energy.
On September 26 that year, the UN General Assembly held its first high-level meeting devoted to nuclear disarmament. In December, through Resolution 68/32, it declared September 26 the International Day for the Total Elimination of Nuclear Weapons. The resolution also called for the urgent commencement of negotiations on a comprehensive convention dealing with nuclear weapons, including their possession, development, production, acquisition, testing, stockpiling, transfer and use or threat of use, as well as their destruction.
The significance of the date is therefore both historical and institutional.
It links the UN’s earliest efforts to control atomic weapons with its continuing campaign for their eventual elimination.
A treaty banning nuclear weapons
In 2017, the international campaign for nuclear disarmament reached another milestone with the adoption of the Treaty on the Prohibition of Nuclear Weapons.
The UN describes it as the first multilateral legally binding instrument for nuclear disarmament negotiated in 20 years. It entered into force on January 22, 2021.
The treaty represented a different approach from traditional arms-control agreements. Instead of concentrating only on limiting arsenals, it established comprehensive prohibitions on activities involving nuclear weapons for states that join it.
However, nuclear-armed states have not joined the treaty, illustrating the continuing divide between the disarmament objective and the security doctrines of states that possess nuclear weapons or rely on nuclear alliances.
The unfinished nuclear question
More than eight decades after Hiroshima and Nagasaki, nuclear weapons remain part of the international security system.
The UN currently estimates that about 12,187 nuclear weapons remain worldwide. It also notes that nuclear-armed states continue to maintain long-term programmes to modernise their arsenals. Although the number of deployed nuclear weapons has declined significantly from the Cold War peak, the UN says that no nuclear weapon has been physically destroyed pursuant to a treaty.
The arms-control framework has also come under strain.
The United States withdrew from the Intermediate-Range Nuclear Forces Treaty in 2019, bringing that agreement to an end. The New Strategic Arms Reduction Treaty, or New START, between the United States and Russia expired on February 5, 2026, without a successor arrangement. The UN notes that this means there are now no agreed limits constraining the strategic nuclear arsenals of the world’s two largest nuclear powers — the first such situation since the 1970s.
At the same time, the international community continues to debate the relationship between nuclear deterrence and disarmament.
Nuclear-armed states and their allies have continued to regard nuclear deterrence as part of their security policies, while the UN and many non-nuclear states continue to emphasise the catastrophic consequences of nuclear use and the objective of complete elimination.
Why September 26 still matters
It is a history of competing forces: deterrence and disarmament, national security and international security, technological development and humanitarian concerns, arms races and arms-control agreements.
The UN first addressed nuclear disarmament in its inaugural resolution in 1946. It subsequently supported treaties limiting testing, efforts to prevent proliferation, nuclear-weapon-free zones and negotiations aimed at reducing nuclear dangers. India, too, has maintained a long-standing public record of advocating universal nuclear disarmament, even while developing and maintaining its own nuclear capability on national-security grounds.
The International Day for the Total Elimination of Nuclear Weapons does not mark the completion of that journey. It marks the persistence of the goal.
In 1945, the destruction of two Japanese cities demonstrated what nuclear weapons could do. In 1946, the newly established United Nations placed their elimination among its earliest disarmament objectives. During the Cold War, the world accumulated vast arsenals while simultaneously building mechanisms to control them. After the Cold War, several countries abandoned nuclear weapons programmes or inherited arsenals, while others continued to regard them as essential to national security.
Today, the international system still contains thousands of nuclear weapons.
That is what gives September 26 its historical significance. It is a reminder that the idea of a world without nuclear weapons is nearly as old as the United Nations itself — and that, despite decades of treaties, negotiations and disarmament initiatives, the objective remains unfinished.
As the UN continues to describe nuclear disarmament as its highest disarmament priority, the question first raised at the beginning of the nuclear age remains unresolved: whether international security can ultimately be built without weapons whose consequences extend far beyond the battlefield.
