The world passed a nuclear milestone this week. And, perhaps surprisingly given the recent run of saber-rattling from the likes of Russia and the United States, it’s a positive one.
“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 noting the milestone.
Wednesday’s watershed means the planet has seen its longest period without a nuclear explosion since the dawn of the nuclear era on July 16, 1945, when the US exploded an atomic device in Alamogordo, New Mexico – the Trinity test – leading up to the atomic bombings of Hiroshima and Nagasaki, Japan, near the end of World War II.
North Korea conducted the world’s last nuclear test on September 3, 2017.
The previous longest period without a test was from May 30, 1998, when Pakistan conducted its last test, to October 3, 2006, when North Korea conducted its first.
Spaulding cautions how fragile this “winning streak” has become, given threats by US President Donald Trump to resume nuclear testing.
“Reopening this Pandora’s box is both unnecessary and unwise,” Spaulding wrote.
“Unrestrained tests lead to competition, instability, and a degree of uncertainty that can scarcely be afforded on top of our existing global precarity,” he wrote.
In another warning sign, Trump has said he’s willing to allow the expiration on February 5 of a US-Russia treaty that caps the number of deployable nuclear weapons each side has.
Russia maintains the world’s biggest stockpile of nuclear weapons with more than 4,300, according to the Stockholm International Peace Research Institute. The US has about 3,700, with Moscow and Washington together accounting for 90% of the world’s nuclear weapons, the SIPRI says.
Since the Trinity test, the world has seen 2,055 nuclear tests by eight nations, according to the Arms Control Association.
The US has conducted the most tests – 1,030, followed by Russia/USSR, 715; France, 210; China and the UK, 45; North Korea, six; India, three; and Pakistan, two.
Those tests have occurred in places ranging from Pacific atolls to deserts in the US and China to the Russian Arctic, often with heavy tolls on human and environmental health.
Widespread nuclear testing stopped in the late 1990s, when the Comprehensive Nuclear-Test-Ban Treaty was opened for signature.
Though it’s never come into force – mainly because the US signed but never ratified it – nations have largely abided by its conditions, with the exception of North Korea, which has been regarded as a rogue state and put under United Nations sanctions.
And since that 2017 test at North Korea’s Punggye-ri test site, much of the world has been on watch for Kim Jong Un to conduct another, given his enormous investment in a missile program that has given him weapons capable of reaching the continental US.
But in recent months, attention has turned to Washington and Moscow as Trump and subsequently Russian leader Vladimir Putin have threatened to restart nuclear testing in their countries.
The US last tested a nuclear weapon on September 23, 1992. And Russia last exploded a nuclear device in 1990, when it was still the Soviet Union.
During a visit to South Korea in October, Trump vowed to begin testing US nuclear weapons “on an equal basis” with Russia and China, saying he had instructed the Defense Department to begin immediate preparations for such testing.
A week after Trump’s announcement, on November 5, Putin directed the Russian military to begin preparing for weapons tests.
Nuclear weapons tests are conducted to gauge the effects of new advances in the bombs or to ensure existing weapons will still work if fired.
Spaulding and other scientists say it’s all unnecessary. That’s because the nuclear powers now have the technology to conduct “sub-critical” tests, which can mimic a nuclear process right up to the point of detonation.
“Advanced nuclear states are technically well beyond the point of exploring whether their weapons will detonate reliably,” he wrote.
Any US testing now brings into question whether Washington has been a reliable steward of its huge nuclear arsenal, according to Spaulding.
“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 US stockpile,” he said.
The fears of renewed nuclear testing are being exacerbated by the impending lapse of the New Strategic Arms Limitation Treaty (START), implemented in 2011, which limits the number of nuclear warheads the US and Russia can deploy to 1,550.
According to a report this week from the Union of Concerned Scientists, those numbers could spike quickly after February 5.
“Within weeks, the United States could field another 480 nuclear weapons at bomber bases. Within months, it could load almost 1,000 additional nuclear warheads onto submarines. And within years, it could load an additional 400 nuclear warheads onto land-based missiles. Russia could do the same, increasing the stakes of political tension and the possibility of deeply catastrophic miscalculations,” the UCS said.
“Both Russia and the United States already have more than enough nuclear weapons to devastate each other many times over. Adding more to the mix increases the chances of an accident, and the consequences of miscalculation or escalation,” said report author Jennifer Knox, a policy and research analyst at the UCS.
START has been on shaky ground since 2023, when Putin suspended Russian participation in it, citing among other reasons US support for Ukraine in the aftermath of Moscow’s full-scale invasion of its neighbor.
Moscow has stopped allowing verification inspections, and the US has reciprocated.
But the Russian leader last September offered to extend observance of START’s limits by a year after February 5.
Trump, however, seems inclined to let it lapse.
“If it expires, it expires,” he said. “We’ll do a better agreement,” he told The New York Times earlier this month, while indicating China should be part of any new pact.
So in this record-setting week, there is more unease than celebration among those who watch nuclear proliferation closely.
“While the world has quietly broken a record for the longest period of time without a nuclear test, it is clear that this stability is fragile,” the UCS’s Spaulding wrote.
