While on his way to meet with Chinese President Xi Jinping for trade negotiations, U.S. President Donald Trump posted a short statement on Oct. 29 that appeared to suggest the United States would shortly resume explosive nuclear testing. “Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis. That process will begin immediately,” he said on Truth Social.
What Trump means by this is unclear at best, and he has now been contradicted by the U.S. energy secretary, leaving the waters even murkier. While some have assumed that this constitutes a direct order to resume explosive testing of nuclear devices, stating that the United States would be testing on an “equal basis” suggests this is more about testing delivery systems, or conducting very-low yield supercritical tests of materials and subcomponents, not warheads themselves.
Trump said that he was starting tests on an “equal basis,” but neither China nor Russia have tested full-scale nuclear weapons since they signed the Comprehensive Test Ban Treaty (CTBT). There are, however, allegations that they may be conducting small-scale “supercritical” nuclear tests, meaning that a test achieves a self-sustaining chain reaction. Trump appears to have referenced these claims during a 60 Minutes interview that aired on Sunday. These tests can theoretically be conducted at scales small enough to evade detection and are very difficult to track via intelligence means.
Small scale supercritical tests also generate less information than full-scale warhead tests, as one cannot directly test the interaction of the various materials inside a nuclear warhead during a full-scale nuclear explosion. Such tests also require specialized facilities that the United States has not invested in, and conducting them may also take years of investment. The United States’ existing subcritical testing facility, PULSE (formally U1a), is currently being modernized at a cost of about $2.5 billion and may not be ready until 2030.
Trump’s announcement also came as Russia tested two of its next-generation nuclear delivery systems, the Burevestnik, a nuclear-powered cruise missile that has some questionable technical characteristics, and the Poseidon, a nuclear torpedo designed to devastate coastal cities. Trump may want the United States to begin flight testing nuclear systems at a rate that matches that of tests in China and Russia.
Both a resumption of nuclear testing and an increase in flight testing could have significant drawbacks, however. For one thing, it’s unclear how quickly the United States could actually resume nuclear testing. On paper, the United States maintains the ability to restart nuclear testing within 24-36 months of a presidential decision. But it’s unclear how realistic that schedule is. The Nevada Test Site is in a state of disrepair, and it would likely require a significant investment in resources.
Nor would full-scale nuclear testing be likely to offer much benefit. For one thing, it would be an abandonment of its commitment to the CTBT, and other signatories like Russia and China might follow suit. China stands to gain the most technical data from a resumption in testing, as its existing testing data is limited—it conducted just 45 nuclear tests before the CTBT, while the United States conducted more than 1,000.
A resumption of testing could also produce serious diplomatic consequences as public opinion in allied countries sours. For almost a decade, the United States has been attempting to manage its reputation on nuclear issues as countries question the slow progress toward nuclear disarmament. Despite commitments to pursue good faith negotiations to disarm under Article VI of the Nuclear Nonproliferation Treaty, progress on nuclear disarmament has reversed over the past decade as Russia, China, and the United States invest in new weapon systems.
Some states have grown impatient by the lack of progress, and support the more demanding Treaty on the Prohibition of Nuclear Weapons (TPNW), which prohibits signatories from producing, transferring, or allowing nuclear weapons to be stored on their territory. The TPNW has been signed by 95 countries and is broadly popular in states allied with the United States, including Australia, Japan, and the Netherlands.
A resumption of nuclear testing may inflame public opinion in these countries and make resisting signing the TPNW politically untenable. This would have serious consequences for the network of alliances that the United States has built to deter Russia and China. For instance, the United States is currently developing nuclear weapons that are designed to be deployed on attack submarines. If states like Australia and Japan were to sign the TPNW, they would be prohibited from basing nuclear weapons on their territory and would ask the United States to declare that visiting attack submarines did not have nuclear weapons onboard.
But the United States has a firm policy of not declaring the presence of nuclear weapons anywhere, and previous attempts by New Zealand to get visiting U.S. warships to declare the presence of nuclear weapons resulted in the United States’ suspending its defense obligations to New Zealand. A similar situation could occur in other allied states if those states join the TPNW, causing serious problems for the United States’ network of alliances and its ability to deter adversaries.
But it’s possible that Trump was not originally suggesting actual nuclear testing. He may want more flight testing of nuclear-capable systems, potentially flight testing in direct response to Russian or Chinese flight tests given the timing of his statements and Russia’s recent tests.
Yet this too could generate significant drawbacks. The United States has worked hard to signal that the flight testing of nuclear-capable systems, such as the regular flight testing of Minuteman III missiles from Vandenberg, are part of routine testing and are not intended to signal anything to adversaries. As part of limiting tensions that missile tests could generate, the United States notifies other countries before tests occur. China recently did the same after its September 2024 ICBM test over the Pacific, progress on risk reduction that should be applauded. Conducting increased flight testing and expressly using it to match Russian and Chinese action would undo that progress.
But the other more pressing problem is that few of the United States’ next-generation nuclear delivery systems are ready for prime time. The Sentinel, the United States’ troubled new intercontinental ballistic missile, was supposed to fly in 2023 but was delayed until 2028. The Nuclear-Armed Sea-Launched Cruise Missile (SLCMN) does not have a first flight test scheduled but is expected to enter service in 2034. A flight test of the system is impossible for the next couple of years as the system is still on the drawing board.
The United States could fly existing nuclear systems instead, but many of them are old and have limited inventories. The Minuteman III missile for instance, 400 of which are currently deployed in silos, is tested regularly. While motors for missiles can always be produced again, airframes and guidance systems are more expensive to make, and various components have been out of production for decades. An increase in testing could exhaust existing American supplies.
None of the United States’ options—from the resumption of nuclear testing to increases in flight testing—are ones that can produce short-term results. All of them would require years of continuous investment, requiring buy-in from Congress and offices across the government. Whatever Trump meant by his statement, the course that follows could be significant and dangerous.
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