Last month, President Donald Trump announced on Truth Social that he had ordered the Department of Defense—or, as he has renamed it, “the Department of War”—to resume nuclear testing for the first time since 1992. His plan to test U.S. nuclear weapons by exploding them will likely cost millions of dollars, risk radioactive leaks, and inflame an international arms race, according to atomic scientists and nuclear policy experts. Worse, they say, it will benefit our adversaries while failing to fundamentally improve weapon safety or reliability.
The plan, which seemed to surprise even Trump’s own military and government officials who work on nuclear matters, reveals troubling ignorance about U.S. nuclear history, posture, and sophistication from a Commander in Chief who wields the sole power to launch 1,419 nuclear weapons and destroy the world.
The United States last exploded a nuclear bomb in 1992, after the collapse of the Soviet Union brought an end to a half-century of mushroom clouds and desert craters at the Nevada Test Site outside Las Vegas. In the years since, national labs have maintained the capability to resume testing in Nevada in twenty-four to thirty-six months if ordered by the President. But they have also acquired massive supercomputers and machinery that can mimic the ignition of thermonuclear bombs without triggering the chain reaction responsible for nuclear explosions.
So confident are the scientists and engineers in the supercomputers’ process that they certify in a letter to the President each year that the U.S. stockpile of weapons will explode as designed. It is accompanied by a similar assessment from the commander of the U.S. Strategic Command that its weapons are in working order and that no underground test explosions are required. This certification process is now thirty years old and stands as a worldwide testament to nuclear deterrence. Prior to Trump’s announcement, top leaders of the U.S. nuclear enterprise said there was no need to explode bombs in tests that cost hundreds of millions of dollars.
“If there is a threat of resumed testing today, it most likely comes from a desire for political posturing rather than technical necessity,” wrote physicist Dylan Spaulding, a senior scientist with the Union of Concerned Scientists. “This is certainly true for advanced nuclear nations who need no longer rely on empirical testing data.”
Los Alamos National Laboratory
Super Computer Panels
The Venado, a supercomputer at Los Alamos National Laboratory.
Trump made his announcement on October 29 as Air Force One was about to land in South Korea for his meeting with Chinese President Xi Jinping. “The United States has more Nuclear Weapons than any other country,” Trump wrote on his social media platform. “This was accomplished, including a complete update and renovation of existing weapons, during my First Term. Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis.”
These three sentences contain four falsehoods: Russia, in fact, has more nukes than does the United States. A thirty-year, $1.7 trillion nuclear modernization program has only just begun. International monitoring finds that only North Korea, with fifty warheads, has tested nuclear weapons in recent years, the last one in 2017. Meanwhile, the United States, using supercomputers, linear accelerators, and lasers, has performed thirty-four “subcritical” tests, the most recent one in May.
Two days after Trump’s post, Energy Secretary Chris Wright told Fox News, “These will be nonnuclear explosions,” a statement contradicted hours later by the President on 60 Minutes. “They test way underground where people don’t know exactly what’s happening with the test,” Trump said. “You feel a little bit of a vibration. They test, and we don’t test. We have to test.”
The last U.S underground test, named “Divider,” took place on September 23, 1992. The five-kiloton bomb, which reportedly tested the ability of the W91 warhead to withstand shocks and fire on re-entry into the atmosphere, was surrounded by instruments that collected data. Like all underground tests, the multimillion-dollar package of equipment and warhead material was entombed by the explosion, which caused the ground to collapse into a telltale crater.
Attempts by The Progressive to clarify Trump’s testing plan or question his errors were met with cordial buck passing by spokespersons at Los Alamos National Laboratory, the National Atomic Testing Museum, the Nevada National Security Site, and the National Nuclear Security Administration. The whole situation has left people inside and outside of the vast nuclear-industrial complex scratching their heads.
“It makes everyone afraid when the guy in charge of America’s nuclear weapons doesn’t appear to know what he’s talking about,” Matthew Bunn, a Harvard professor who specializes in foreign policy and nuclear technology, told The New York Times.
Trump’s announcement was swiftly criticized by arms control organizations. CNN reported on November 14 that Energy Secretary Chris Wright, National Nuclear Security Administration leader Brandon M. Williams and officials from the US National Laboratories were headed to the White House “to dissuade” Trump from testing.
John Erath, the senior policy director for the Washington-based Center for Arms Control and Non-Proliferation, told Defense News that if the United States were to break the global moratorium on nuclear testing, other nations including Russia, China, North Korea, India, and Pakistan would likely follow suit. “The dominoes would fall,” Erath predicted. “It would not be advantageous to U.S. foreign policy in any way.”
During the Cold War, the United States exploded 1,054 nuclear weapons, mostly at the Nevada Test Site. That site, now called the Nevada National Security Site, was chosen by President Harry Truman in 1950, fifteen months after the Soviet Union detonated Joe-1, its first atomic bomb. Joe-1was a copy of the Nagasaki “Fat Man” bomb, stolen from the United States by spy Klaus Fuchs. By that time, the United States had 170 bombs in its stockpile.
Five months after the Joe-1 detonation, Truman authorized work on the hydrogen bomb. The first one was exploded in 1952 on the Enewetak atoll, and followed nine months later by the first Soviet hydrogen bomb. With the exception of 106 nuclear tests in the Pacific region, three tests in the South Atlantic, and seventeen elsewhere in the United States, all American nuclear tests were conducted at the Nevada site.
The mushroom clouds from these detonations became a tourist attraction, visible from Las Vegas, sixty-five miles away. Visitors “would gather on casino balconies to sip atomic-themed cocktails while watching nuclear explosions,” one recent article reported. As Glen McDuff, a retired Los Alamos scientist, noted, “A nuke was a pretty good show.”
Atomic scientists celebrated successful tests, creating what Spaulding of the Union of Concerned Scientists, in an interview with The Progressive, calls “an almost more cowboy ethos.” Until 2001, the two bomb-designing laboratories, Los Alamos and Lawrence Livermore, with separate staffs at the Nevada Test Site, developed, tested, and maintained their own bombs. In 2001, for the first time since its founding in 1952, Lawrence Livermore was tasked with refurbishing the “nuclear explosive package” of the W88 cruise missile warhead, a Los Alamos design.
A total of eighty-six Nevada tests above ground and fourteen underground tests released significant radiation between 1951 and 1992 creating fallout that spread across the country, with major impacts in neighboring Utah counties where children drank milk contaminated with radioactive iodine from cows grazing on fallout-covered grass.
Researchers using a National Cancer Institute evaluation of thyroid glands estimated that 49,000 people, almost all under the age of twenty at the time of the test, could develop thyroid cancer from fallout exposure. Nationwide, an estimated 1,800 leukemia deaths “might eventually occur” from Nevada and global fallout. Another 22,000 radiation-related cancers, “half of them fatal, might eventually result from external exposure from [the Nevada Test Site] and global fallout,” the researchers reported in American Scientist.
Prompted by fallout dangers, the proliferation of nuclear weapons, and the 1962 Cuban Missile Crisis, negotiations were begun to end nuclear tests. Atmospheric tests ended under the 1963 Limited Test Ban Treaty, signed by the United States, Great Britain, and the Soviet Union. The 1996 Comprehensive Test Ban Treaty banned all nuclear tests. The United States and China signed the treaty but have not ratified it. Russia revoked its ratification in November 2023. In his justification for the resumption of testing, Trump claims that Russia and China are testing, which they, and even Trump’s own nominee to lead the military’s nuclear command STRATCOM, deny.
Following the end of the Cold War, the United States began dismantling thousands of warheads, hoping for a peace dividend. By the fall of 2023, 90 percent of the nation’s stockpile had either been taken apart, or “retired”—removed from its delivery platform. Some 20,000 plutonium “pits,” the H-bomb igniters, were stored in igloos at Pantex, Texas. That leaves approximately 3,700 warheads in the U.S. nuclear stockpile, with 1,670 actually deployed and on alert on intercontinental missiles and bomber bases.
With no new weapons being made, and no testing, the nuclear enterprise fell into a funk. In 1995, on the fiftieth anniversary of the bomb, The Denver Post reported that the U.S. Department of Energy “spends more money cleaning up than creating weapons, with 40 percent going for administration.”
Jason Laurea/LLNL
The National Ignition Facility at Lawrence Livermore National Laboratory, where lasers are creating fusion experiments that mimic the sun, both for power and for analysis of nuclear explosions.
“We actually had the nuclear weapons and computer codes people get together and lay out what we needed to do to create the sort of modeling and simulation needed in the absence of nuclear testing to help us keep confidence in the stockpile,” said Siegfried Hecker, a retired director of Los Alamos. The result was a multi-billion dollar toolset that is still being installed at Lawrence Livermore, the National Ignition Facility, built to create fusion, lasers bombard BB-sized capsules filled with deuterium and tritium to mimic what happens in a thermonuclear bomb, Spaulding tells The Progressive.
Los Alamos, meanwhile, installed a massive, permanent complex called Principal Underground Laboratory for Subcritical Experimentation (PULSE) at a cost of more than $2.5 billion. Dug 1,000 feet below the desert, the maze of tunnels two miles long connects to a control room.
One of its tasks is to answer a long-standing dispute over the quality of bombs in the stockpile. The PULSE machinery can bombard microscopic bits of plutonium with neutrons or electrons and yield high-speed X-ray images of the metal, without blowing it up. With that 400-foot long machine, says Spaulding, they can compare the performance of aging plutonium pits with newly forged ones made at Los Alamos and what their supercomputer simulations say they should be.
Ultimately, the continued investment in nuclear technology is a psychological deterrent that may be as powerful as a new warhead, experts tell The Progressive.
“Yes, we have weapons that we’ve designed on alert and ready to be used, God forbid, but also that if people find weaknesses or gaps in our deterrent that they could try and exploit, we have the capability to overcome them,” says Thomas Mason, director of the Los Alamos Laboratory. “When we talk about the new supercomputer that we have deployed at Los Alamos and its computational capabilities, that kind of scientific competence underpins the fact that another country may seek to find ways to circumvent or avoid the deterrent that's there, but we’re going to get there first, and we’re going to figure it out.”
Spaulding, a frequent critic of U.S. nuclear policy, argues that high-tech stockpile stewardship demonstrates the credibility of U.S deterrence “through its scientific capabilities, rather than numbers of warheads or the yields of those warheads. By building facilities like this underground facility at Nevada that does these tests that’s also a way for the United States to flex its muscles and say, you know, look what we can do. In many ways, that projects more power than the design number of the warhead or how many you produce.”