On September 26, 1983, Lieutenant Colonel Stanislav Petrov did not know that he would help save the world. At his post inside the Serpukhov-15 bunker, he saw five intercontinental ballistic missiles (ICBMs) from the United States appearing on the automated nuclear early-warning system, heading toward the Soviet Union. Tracking systems confirmed the attack. But Petrov thought that an attack involving only five missiles was inconsistent with a US nuclear first strike.
Had he reported the alert up his chain of command, the potential risk of triggering the Soviet nuclear doctrine would have been extremely high. His instinct told him that the system was malfunctioning, that the attack was not real. He was right: “the early-warning system had mistakenly interpreted sunlight reflected off clouds as missile launch signals” (missiles).
Two decades earlier, during the Cuban Missile Crisis in 1962, John F. Kennedy, Nikita Khrushchev and a small number of actors on the ground in the Cold War theatre played with humanity’s fate during several days in which every move seemed capable of triggering further escalation.
Once again, it was a Soviet officer, Vasili Arkhipov, chief of staff of the submarine brigade aboard the B-59 submarine, who helped avert catastrophe. On October 27, 1962, when US destroyers began harassing the submarine with depth charges, its commander, Valentin Savitsky, believed that war had begun and ordered a nuclear-armed torpedo to be prepared. Arkhipov managed to convince him that this was a mistake and prevented the launch.
Just a few weeks after the Petrov incident, in November 1983, the NATO Able Archer 83 exercise, which simulated the transition from conventional warfare to the coordinated use of nuclear weapons, came close to triggering an escalation. Some elements of Soviet intelligence interpreted the exercise as a move towards a nuclear first strike, and the USSR raised the alert level of some of its forces. Lieutenant General Leonard Perroots, the US Air Force intelligence chief in Europe, recommended against raising the US alert level, arguing that the situation should be monitored without escalating an already tense situation.
The logic of Mutually Assured Destruction was very much present during those years. The capacity for destruction served as a deterrent, but it also meant that any miscalculation, false alarm or unintended escalation could have irreversible consequences.
Since the end of the Cold War, there have been nuclear crises and periods of heightened tension, but the strategic context has changed profoundly from the most dangerous moments of those years. Even so, the risk remains. According to the Federation of American Scientists, in 1986 the world possessed 70,374 nuclear warheads. Today, in 2026, that number has fallen by 83%, to 12,187.
In 2023, Russia stopped providing its semi-annual updates on its strategic nuclear arsenals covered by the New START Treaty. The United States responded by suspending its own reporting to Russia.
Finally, the treaty expired on February 5, 2026, and has not been replaced. For the first time in decades, the United States and Russia are operating without a legally binding bilateral treaty limiting the deployment of their nuclear weapons. Vladimir Putin proposed extending the central limits of New START for one year, but Donald Trump rejected this option, calling instead for a “new and better” agreement, which has yet to materialize.
NATO continues to consider nuclear weapons a central component of its strategy and is modernizing its deterrence capabilities. Meanwhile, Russia, China, India, Pakistan, North Korea and Israel continue in 2026 with programmes to modernize their nuclear arsenals.
September 26, the International Day for the Total Elimination of Nuclear Weapons, is an opportunity to remember that the risk is far from gone. Reducing the number of nuclear weapons by around 83% is good news. But today is not about celebrating that there are fewer of them. It is about remembering that more than 12,000 still exist.
True success will not be reaching 99%. It will be reaching 100%. Achieving that will require reciprocal agreements, effective verification mechanisms and security guarantees capable of ensuring that disarmament does not create new risks and vulnerabilities.
That is precisely what September 26 is an opportunity to remember: we have come a long way, but the goal is still far from being reached.
Chris Moya is a software developer with postgraduate studies in Society and Technology, Social Conflict Management, and Restorative Justice. He also has extensive experience in the social sector, human rights advocacy, and peacebuilding.