Trump orders the Pentagon to conduct nuclear weapons tests

Donald Trump has introduced a new element of concern in relations with Russia and China: the nuclear factor. In a confusing message on social media, just minutes before beginning his meeting in South Korea with Chinese President Xi Jinping on Thursday to discuss trade, the U.S. leader announced that he had ordered the Pentagon to conduct nuclear weapons tests “immediately.” If these go ahead, they would be the first since 1992.

“Because of other countries testing programs, I have instructed the Department of War [Department of Defense] to start testing our Nuclear Weapons on an equal basis. That process will begin immediately,” Trump wrote.

The message, although it does not mention any specific country, comes hours after Russian President Vladimir Putin confirmed on Wednesday that the Kremlin has successfully tested a nuclear-powered super torpedo, the Poseidon, capable of triggering huge radioactive tsunamis that could wipe out large coastal areas.

Trump did not make it clear whether he was talking about tests with nuclear warheads — something that could destabilize decades of efforts against weapons proliferation — or whether he was referring only to the launch systems and missiles used to transport them, but without a nuclear payload on board. Adding to the confusion is Trump’s reference to the Pentagon as the agency that received the order, even though the Department of Energy is responsible for conducting nuclear tests.

“The United States has more Nuclear Weapons than any other country,” Trump stresses in his message, noting that Russia is second and China “a distant third, but will be even within five years.”

According to official data from the Department of Energy, the United States had 3,748 nuclear warheads in 2023. Russia had 4,309 at the beginning of 2025, according to data published by the scientific NGO Bulletin of Atomic Scientists. China has doubled its warheads, from 300 in 2020 to 600 in 2025, and the Department of Defense estimates that by 2030 it will have exceeded 1,000.

Trump’s announcement came moments before his arrival in South Korea, where he met with Xi Jinping on Thursday. When asked by reporters about the order he had just announced, the U.S. president declined to comment.

Tension with Russia

The test launches from a submarine of the Russian Poseidon super-torpedo — a 24-meter-long projectile capable of carrying a nuclear warhead and operating in part as an underwater drone — have taken place in a context in which the relationship between Trump and Putin appears to be deteriorating, after the U.S. president announced the cancellation of a bilateral summit in Budapest due to the Russian leader’s refusal to sit down and negotiate peace in Ukraine.

The existence of Poseidon was announced by Putin back in March 2018. On October 21, Russia also conducted tests of the new Burevestnik cruise missile, but has so far refrained from conducting nuclear detonations.

The United States conducted its last nuclear weapons test on September 23, 1992, at the end of the Cold War, at its National Security Center in Nevada. Since then, it has observed a voluntary moratorium on underground explosions.

The purpose of such a test is, at least in theory, to verify the proper functioning of a prototype or to ensure that older weapons that have been in storage for some time are still effective. But it can also be a way to flex military muscle in front of rival countries.

The three-decade-old moratorium has been one of the pillars of nuclear nonproliferation, but Trump’s order could blow those efforts out of the water.

Advocates of nuclear arms control immediately began criticizing Trump’s announcement. In a message on social media, Daryl Kimball, executive director of the Arms Control Association in Washington, said: “Trump is misinformed and out of touch. The U.S. has no technical, military, or political reason to resume nuclear explosive testing for the first time since 1992.”

On X, Democratic Senator Ed Markey said: “The U.S. has not conducted a nuclear test since 1992 and we must not resume. This is a reckless decision that will only make us less safe and lead to a new nuclear arms race.”

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