In a stunning and deeply controversial move, United States President Donald Trump has instructed the Pentagon to resume nuclear weapons testing “on an equal basis” with other countries’ programs. If the order implies the return of explosive nuclear tests — halted by the U.S. since 1992 — it would mark a historic reversal of decades of international restraint and could spark a new and dangerous era of nuclear competition.
The decision, according to officials familiar with the President’s directive, is being justified on grounds of “strategic parity.” Trump reportedly believes that if other nations, notably Russia and China, continue to refine their nuclear arsenals, the U.S. should not be bound by “outdated treaties” or “self-imposed limits.”
But nuclear experts and global security analysts are warning that such a step could have catastrophic geopolitical, environmental, and humanitarian consequences. “This would be a deeply regrettable and profoundly destabilizing move,” said a former senior U.N. disarmament official. “It would invite reciprocal actions by other nuclear powers and shred what little remains of the post–Cold War arms control regime.”
If carried out, Trump’s directive would effectively end the 33-year moratorium on explosive nuclear testing observed by the United States since 1992. It would also undermine the Comprehensive Nuclear-Test-Ban Treaty (CTBT) — one of the world’s most widely supported disarmament agreements, signed by 187 nations.
The United States signed the CTBT in 1996 but never ratified it. Nevertheless, as a signatory, Washington is legally bound not to act in a manner that defeats the treaty’s object and purpose.
Nuclear testing, once used to refine weapons designs and assess blast effects, has a grim legacy. Since the dawn of the atomic age, more than 2,000 nuclear tests have been conducted worldwide, resulting in widespread radioactive fallout, environmental contamination, and long-term health effects on civilian populations.
Even underground tests — which the Partial Test Ban Treaty of 1963 allowed — carry severe risks. Venting and seepage of radioactive materials into the air and groundwater can occur, potentially affecting vast regions far from the test site. “There is no such thing as a completely safe nuclear test,” warns a senior environmental scientist with the International Atomic Energy Agency.
During the early decades of the Cold War, testing was essential to understanding how nuclear weapons functioned — measuring blast yields, shockwaves, and thermal radiation at varying distances. But by the 1980s and 1990s, advances in computer modeling and subcritical testing rendered explosive tests largely obsolete.
The United States ceased testing in 1992; France followed in 1996. Russia and China are not known to have conducted any nuclear detonations since the 1990s. Only North Korea has openly tested nuclear devices this century, the last in 2017.
“Technological advances made full-scale nuclear detonations unnecessary,” says a former Los Alamos scientist. “The leading powers can now validate new designs and maintain their arsenals through simulation and advanced materials testing. Explosive testing is a relic — and reviving it would serve no scientific or strategic need.”
The timing of Trump’s order could not be more fraught. Global arms control frameworks have been collapsing one after another. The Intermediate-Range Nuclear Forces (INF) Treaty, which eliminated an entire class of nuclear missiles, expired in 2019. The Open Skies Treaty, which allowed mutual aerial reconnaissance to build transparency, followed suit in 2020.
Today, only one major arms control agreement remains — the New START Treaty — limiting the deployed strategic arsenals of the U.S. and Russia. That accord, set to expire in February next year, remains unrenewed. While Russian President Vladimir Putin has offered to extend it by one year, the U.S. insists that China must also be included in any future framework — a condition Beijing has rejected outright.
Should New START lapse without replacement, there would be no legally binding limits on the world’s two largest nuclear arsenals for the first time since 1972.
Meanwhile, the global nuclear landscape has grown increasingly volatile. Russia has unveiled new doomsday weapons, including a nuclear-powered, nuclear-armed cruise missile reportedly tested successfully last month. China is rapidly expanding its warhead stockpile and building hundreds of new missile silos. The United States, for its part, has just completed assembly of the new B61-13 nuclear gravity bomb, designed for both strategic and tactical aircraft.
All nine nuclear-armed states — the U.S., Russia, China, France, the U.K., India, Pakistan, North Korea, and Israel — are investing heavily in more advanced, accurate, and concealable nuclear delivery systems. Analysts warn that these technological refinements, especially in tactical and hypersonic weapons, may lower the threshold for nuclear use.
For decades, nuclear deterrence rested on a fragile balance reinforced by mutual restraint. But recent years have seen a disturbing normalization of nuclear rhetoric and posturing. Russia has repeatedly issued nuclear threats during its war in Ukraine. Israel has hinted at nuclear readiness amid escalating Middle East tensions. Even the United States has increased the operational readiness of certain warheads, blurring the line between deterrence and coercion.
“The danger today is not just in deliberate nuclear war but in miscalculation and accident,” says a U.S. nonproliferation expert. “When warheads are placed on high alert — ready to launch within minutes — the risk of a mistaken or unauthorized use skyrockets.”
Indeed, according to the Stockholm International Peace Research Institute (SIPRI), the number of “usable” nuclear weapons — those deployed, stockpiled, or on alert — has begun to rise again after decades of decline. The notion that the world is edging closer to the nuclear brink is no longer theoretical.
Beyond geopolitical calculations lies the devastating human and ecological cost. Past nuclear tests left a legacy of radioactive contamination, genetic damage, and displaced communities — from the Marshall Islands and Nevada to Kazakhstan and French Polynesia.
Even underground explosions can vent radioactive gases, including xenon and krypton isotopes, detectable thousands of kilometers away. Over time, fissures and fractures in rock strata can allow radionuclides to leach into groundwater systems, posing long-term health hazards.
The idea that the U.S. might reopen such test sites — likely at the Nevada National Security Site — has triggered strong opposition from environmental groups, scientists, and local leaders. “Resuming nuclear tests is reckless, unnecessary, and immoral,” said a Nevada congressman. “We’ve already poisoned our lands once. We cannot repeat that mistake.”
Despite these grim developments, a glimmer of progress remains. The Treaty on the Prohibition of Nuclear Weapons (TPNW), which entered into force in 2021, represents the first legally binding global instrument to comprehensively ban nuclear weapons. Signed by over half of the world’s nations, it envisions the total elimination of nuclear arsenals.
While none of the nuclear-armed states have joined the treaty, it has reenergized the global disarmament movement and reaffirmed the moral illegitimacy of nuclear deterrence.
“The TPNW is the clearest expression of humanity’s will to be free from the shadow of annihilation,” said a spokesperson for the International Campaign to Abolish Nuclear Weapons (ICAN), the 2017 Nobel Peace Prize laureate. “Every step backward by nuclear powers only strengthens the case for total prohibition.”
The Doomsday Clock, maintained by the Bulletin of the Atomic Scientists, measures humanity’s proximity to catastrophe. This year, it was set at 90 seconds to midnight — the closest it has ever been, reflecting the combined dangers of nuclear war, climate change, and emerging technologies.
Trump’s nuclear testing order, if implemented, could move the clock even closer. It would signal the collapse of the last taboos restraining nuclear brinkmanship, ignite reciprocal tests by Russia and China, and bury decades of painstaking arms control diplomacy.
“The world has spent half a century trying to step back from the nuclear abyss,” one disarmament veteran said. “To start testing again is to take a giant leap toward it.”
As the international community braces for the potential fallout — diplomatic, environmental, and literal — one truth stands starkly clear: the return to nuclear testing is not progress. It is regression to an age of fear, when the world lived one miscalculation away from annihilation.
