Trump’s Nuclear Testing Threat: What Does it Mean?

Last week, on October 29, President Donald Trump announced via a late night post on his social media site Truth Social that the U.S. would “start testing our Nuclear Weapons on an equal basis [with other nations].” The post caused alarm among advocates and policymakers as experts quickly weighed in to read the tea leaves of the president’s statement and highlight its numerous inaccuracies.

For example: the U.S. does not, as Trump claimed in his post, have “more Nuclear Weapons than any other country.” That dubious honor belongs to Russia which, according to the Federation of American Scientists, has an inventory of 4,309 nuclear warheads to the U.S.’ 3,700. Further, Trump’s claim that American testing is a reaction to “other countries [sic] testing programs” is questionable. The U.S. accused Russia of not upholding a zero-yield standard in 2021, but in general, today’s leading nuclear powers—Russia, China, and the U.S.—have maintained a moratorium on full-scale explosive testing since the 1990s. In fact, the only country to conduct Cold War-style nuclear testing in the 21^st century is North Korea.

Before examining Trump’s announcement and what it meant, though, it’s helpful to re-familiarize ourselves with the history of nuclear weapons testing.

Nuclear testing: a brief retrospective

The first ever nuclear test detonation, codenamed Trinity, took place in the deserts of New Mexico on July 16, 1945 as part of the Manhattan Project. This was a feasibility test set to answer one question: could the bomb work as designed?

It did. The bomb produced an explosive yield of 25 kilotons, or about 25,000 tons of TNT. The following month, the U.S. Army Air Force dropped two atomic bombs on the Japanese cities of Hiroshima and Nagasaki, killing over 100,000 people. The nuclear age had begun.

During the Cold War, the U.S., Soviet Union, China and other states all conducted numerous nuclear tests. Washington led the pack with a staggering 1,030 detonations followed by the Soviets with 715 and the French with 210. China has only conducted 45 nuclear tests. More than 500 of all these were atmospheric tests, meaning they were nuclear detonations that occurred in the open—usually at remote sites, although the environmental and health impacts on local communities was still significant. Later tests were subterranean – i.e. underground. The British, Indians, Pakistanis, North Koreans and (possibly) South Africans and Israelis have all conducted their own tests. In total, there have been 2,056 nuclear tests since 1945.

On the heels of the prolific atmospheric testing of the early Cold War, the Partial Test Ban Treaty (PTBT) came into force in October 1963, banning all nuclear test detonations except those that occurred underground—although China, France, and possibly Israel and South Africa still conducted them afterwards.

As the Cold War wound down, so too did nuclear testing. The Soviets, soon to be the Russian Federation, conducted their last nuclear test in 1990. The last U.S. nuclear test was held in 1992, and the last Chinese test was in 1996. All were subterranean. In 1996, the Comprehensive Nuclear Test Ban Treaty (CTBT) banned all nuclear testing, however it never entered into force. It was signed, though never ratified, by the U.S. and China. Russia both signed and ratified it, only to de-ratify in 2023 as tensions with Washington grew.

Despite periodic subterranean tests by the North Korean regime, the norm against nuclear testing has more or less held since the 1990s. Yet now, as tensions between the world’s great powers grow, so too does the temptation to break that norm. Last week, President Trump may have done just that.

What did Trump mean in his Truth Social post?

As with so many of President Trump’s statements, the meaning of his announcement was not immediately clear. Some suggested that Trump may have simply meant flight testing of delivery systems—i.e. missiles—but not detonations of warheads. The U.S., however, already conducts routine Minuteman III intercontinental ballistic missile (ICBM) tests, so it’s not clear what good more flight testing would do. Indeed, since Trump’s announcement, the U.S. has carried out another flight test of a Minuteman III missile without a warhead. Others have naturally worried nuclear detonations are truly set to resume.

On November 2, Secretary of Energy Chris Wright tried to offer some clarification, telling Fox News that the U.S. would not resume nuclear detonations but would instead conduct “subcritical” tests in response to similar ones that the Russians have carried out. A subcritical test skirts, but doesn’t violate, the CTBT by using conventional explosives to compress fissile material—usually plutonium-239—in a way mirrors how a nuclear bomb works but which importantly does not produce the chain reaction that causes a nuclear explosion.

However, in a CBS interview released on November 3, the president, when asked whether or not the U.S. would resume nuclear tests, muddied the waters again by saying, “we’re going to test nuclear weapons like other countries do, yes… Russia’s testing nuclear weapons… And China’s testing ’em too. You just don’t know about it.” Again, it’s not clear what kind of testing Trump is referring to here. Russia and China have not carried out nuclear detonations since the 1990s, as we know. But China may have and Russia definitely has conducted subcritical tests. Is this what President Trump means by carrying out tests “on an equal basis” with other countries? Or is it meant to be a threat to conduct a nuclear test, a sort of tripwire that will be triggered if Russia or China do so first? All three countries have been updating their test sites, so perhaps Trump is warning about the consequences if the moratorium is broken. But again, none of this is certain.

Importantly, Project 2025, which has provided the blueprint for Trump’s second term, explicitly promoted the idea of resuming, or at least preparing to resume, nuclear yield testing so what is clear is that this policy option is very much on the White House’s radar.

What if the president does make the decision to return to nuclear testing? Such a move would pose many problems and risks. First, the U.S. simply isn’t ready to resume testing for the first time since 1992. Ploughshares grantee Daryl Kimball of the Arms Control Association argues it could take 36 months or more to get the test site up-and-running, to say nothing of the cost in money and resources. Second, testing would deepen an already worrisome arms race with Russia and China, and all but guarantee that those states conduct tests of their own. Third, a return to testing would have limited benefits for the U.S. but would be of particular benefit to China. Beijing did not conduct nearly as many tests as the U.S. and Soviets during the Cold War and would greatly profit from the additional testing data. Fourth, there are devastating environmental concerns. The risks of radiological contamination, for one, present a serious hazard even if the tests are carried out underground.

No matter how President Trump’s recent announcement is interpreted, his posturing is a bad sign for the state of the global nuclear arms race and another blow to the norms that have kept nuclear weapons in their silos. A resumption of explosive nuclear testing would increase threats to the environment, nearby communities, American interests, and global security. As the nuclear arms race continues to heat up, the risks are beyond dangerous—they’re existential.