The world quietly crossed a historic milestone this week: for the first time since the dawn of the nuclear era, humanity has gone more than eight years without a nuclear weapons test. Yet despite this rare achievement, experts warn that the record-setting period of calm is fragile, with looming threats from major powers and the potential erosion of arms control agreements.
“As of today, the world has gone eight years, four months, and 11 days without a nuclear test. From now on, every day without a nuclear explosion will set a new record,” Dylan Spaulding, senior scientist at the Union of Concerned Scientists (UCS), wrote in a blog post Wednesday, highlighting the milestone.
This latest record stretches back to North Korea’s last nuclear test on September 3, 2017. It surpasses the previous longest hiatus, which lasted from May 30, 1998, when Pakistan conducted its last nuclear test, until October 3, 2006, when North Korea conducted its first.
The milestone, Spaulding notes, is “a remarkable achievement,” but one that exists under constant threat from political tensions and policy shifts in Washington, Moscow, and Pyongyang.
The longest period without a nuclear detonation is an anomaly in an era that has otherwise been defined by nuclear weapons proliferation and periodic testing. Since the first detonation—the Trinity test on July 16, 1945, in Alamogordo, New Mexico—the world has seen 2,055 nuclear tests conducted by eight nations, according to the Arms Control Association. The United States leads with 1,030 tests, followed by the Soviet Union/Russia with 715, France with 210, and China and the United Kingdom with 45 each. India has tested three times, Pakistan twice, and North Korea six times.
These detonations have spanned the globe, from remote Pacific atolls to the deserts of Nevada, China, and Russia’s Arctic regions, often with heavy human and environmental costs. Fallout from atmospheric testing has caused long-term health problems, while underground tests, though less visibly destructive, have left geological scars and radiation risks.
Widespread nuclear testing largely ceased in the late 1990s with the opening for signature of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). While the treaty has never entered into force—principally because the U.S. signed but never ratified it—the vast majority of nations have adhered to its provisions, with North Korea standing as the major exception.
Attention initially focused on North Korea as the last nation to conduct a test, given its extensive missile program and history of provocations. Since 2017, observers have watched closely for any sign that Kim Jong Un might conduct another detonation. Pyongyang has invested heavily in weapons capable of reaching the continental United States, and even a single test could trigger widespread regional and global concern.
Yet in recent months, the focus has shifted from Pyongyang to Washington and Moscow. Former U.S. President Donald Trump and Russian President Vladimir Putin have both made statements hinting at potential nuclear testing, reviving fears that the world’s “winning streak” could be short-lived.
The United States last conducted a nuclear test on September 23, 1992, while Russia’s most recent explosion occurred in 1990, when it was still the Soviet Union. During a visit to South Korea in October, Trump stated that the U.S. would resume testing on “an equal basis” with Russia and China, claiming that he had instructed the Defense Department to begin preparations. Within a week, Putin also ordered the Russian military to prepare for weapons tests.
These tests, in principle, allow nations to evaluate the performance and reliability of their arsenals, especially as new warheads are developed. However, experts argue that modern nuclear powers have no practical need for live detonations. Sub-critical tests—experiments that simulate nuclear reactions without causing a full explosion—allow nations to assess their stockpiles with minimal risk.
“Advanced nuclear states are technically well beyond the point of exploring whether their weapons will detonate reliably,” Spaulding explained. Conducting actual nuclear tests now, he warns, could undermine confidence in existing stockpiles rather than bolster it. “While the Trump administration may view a test as a contribution to deterrence, it may actually have the opposite effect by projecting an irreconcilable lack of confidence in the U.S. stockpile,” he said.
The fragility of the record is compounded by the pending expiration of the New Strategic Arms Reduction Treaty (New START) on February 5. Implemented in 2011, the treaty limits the number of nuclear warheads that the United States and Russia can deploy to 1,550 each. Without this cap, both nations could rapidly expand their arsenals.
A report from the UCS this week notes that within weeks, the U.S. could field another 480 nuclear weapons at bomber bases, and within months, it could add almost 1,000 warheads to submarines. Russia could similarly expand its deployed stockpile. “Both Russia and the United States already have more than enough nuclear weapons to devastate each other many times over,” said Jennifer Knox, a policy and research analyst at UCS. “Adding more to the mix increases the chances of an accident, and the consequences of miscalculation or escalation.”
The treaty has been under strain since 2023, when Putin suspended Russian participation, citing U.S. support for Ukraine after Russia’s full-scale invasion. Moscow has since blocked verification inspections, and the U.S. has reciprocated. While Putin offered a potential one-year extension, Trump appears inclined to let the agreement lapse. “If it expires, it expires. We’ll do a better agreement,” he told The New York Times, indicating that China should be included in any future negotiations.
The milestone of over eight years without a nuclear test is remarkable not just for its symbolic value but for the tangible reduction in nuclear danger. The absence of detonations has limited environmental harm, reduced radiation exposure, and helped maintain a degree of geopolitical stability.
Yet the record underscores how precarious that stability is. Political shifts in Washington and Moscow, coupled with North Korea’s potential ambitions, could quickly reverse progress. Experts argue that renewed testing by major powers could trigger a cascade of nuclear modernization programs, escalating tensions and raising the risk of miscalculation.
Spaulding warns that returning to nuclear testing is “both unnecessary and unwise.” He describes it as reopening a Pandora’s box, introducing competition, instability, and uncertainty into an already volatile global landscape.
The eight-year hiatus is unprecedented in the nuclear era. Since the first Trinity test in 1945, the world has witnessed cycles of rapid nuclear expansion and periodic moratoriums. The previous longest period without tests—from 1998 to 2006—was broken by North Korea, highlighting the vulnerability of any informal international norms.
The historical trajectory shows a clear pattern: nuclear testing has always carried risks, not only from immediate destructive power but also through environmental contamination, health hazards, and the destabilization of international security. In this light, the current record is a quiet triumph, demonstrating that even in a world with thousands of nuclear weapons, restraint is possible.
Despite the milestone, experts urge vigilance. The combination of the New START treaty’s pending expiration, political rhetoric favoring testing, and North Korea’s ongoing missile development underscores that the global nuclear landscape remains tense.
“The world has quietly broken a record for the longest period of time without a nuclear test, but it is clear that this stability is fragile,” Spaulding said.
As governments navigate the coming months, the international community faces a stark choice: safeguard the hard-won record of restraint or risk reversing decades of incremental progress. For now, the world can mark a rare victory in the nuclear age, but it is one shadowed by uncertainty, reminding humanity that the legacy of the atomic bomb remains as potent and perilous as ever.
Eight years, four months, and 11 days may seem like a long time, but in the context of the nuclear era, it is a fleeting respite. The milestone is a reminder that human decision-making, political stability, and international cooperation are as crucial to nuclear safety as any treaty or technological safeguard. Maintaining the streak of no nuclear detonations will require continued restraint, diplomacy, and vigilance—qualities that remain in peril as global tensions rise.
The world has reached a historic benchmark in nuclear restraint, yet the fragile calm of this record-setting period underscores the enduring threat of proliferation, geopolitical tension, and the very real consequences of miscalculation in the nuclear age.
