On October 29, 2025, just minutes before his meeting with Chinese President Xi Jinping in Busan, South Korea, U.S. President Donald Trump said the U.S. would “start testing our nuclear weapons on an equal basis with other nations”. While returning to Washington, Mr. Trump told reporters, aboard Air Force One, “We have halted it for years – many years. But with others doing testing, I think it’s appropriate that we also do.” Back in the U.S., Mr. Trump repeated his claims in an interview. “Russia is testing; China is testing, but they don’t talk about it… And certainly North Korea has been testing. Pakistan has been testing.”
Mr. Trump is correct about North Korea, which has tested multiple nuclear weapons in the new century. But other nuclear powers, including the U.S., China and Russia, have maintained a moratorium on weapons testing since the 1990s. They, however, have tested weapons that can carry nuclear warheads. Mr. Trump’s announcement came immediately after Russia announced that it successfully tested a nuclear-powered cruise missile (Burevestnik) and an undersea torpedo (Poseidon). Both are designed to overcome American missile defence systems and can carry nuclear warheads. But those were not nuclear detonation tests.
Age of tests
The last time Russia tested a nuclear weapon was in 1990, when the Soviet Union was still alive. The last American nuclear bomb test was held in 1992, and the last Chinese test was in 1996. In 1996, the Comprehensive Test Ban Treaty (CTBT) banned all nuclear tests, but it never came into force as the required number of countries did not ratify it. The U.S. and China have signed the treaty but never ratified it. Russia had signed and ratified it, but in 2023, amid mounting tensions with the U.S., it decided to de-ratify it.
Russia remains the world’s largest nuclear power with an inventory of 4,309 warheads, according to the Federation of American Scientists. The U.S. comes second with 3,700 weapons, while China, which is ramping up its nuclear arsenals, is believed to have more than 1,000 warheads. Historically, the U.S. has carried out the most number of nuclear tests — 1,030 detonations, followed by the Soviet Union (715) and the French (210). China has conducted more than 45 nuclear tests. In total, there have been 2,056 nuclear tests since ‘Trinity’, the first nuclear detonation by the U.S.
Debate in the U.S.
In the U.S., the debate on whether the country should resume nuclear tests has been raging for some time. Last year, Robert C. O’Brien, a National Security Adviser under Mr. Trump’s first term as President, wrote in Foreign Affairs magazine that the U.S. should restart nuclear testing to address Russia’s and China’s “growing and modernising” arsenals”. ‘Project 2025’, a political initiative published by the pro-Trump Heritage Foundation in 2023, called resuming or at least preparing to resume nuclear testing. Those who support tests argue that it is important to bolster the country’s nuclear deterrent-tests can prove that nuclear arsenals actually work, and provide critical data allowing countries to build more powerful, compact and specialised warheads.
On November 2, U.S. Secretary of Energy Chris Wright said the U.S. would not resume nuclear weapons tests but would conduct “subcritical tests”. A subcritical test uses conventional explosives to compress fissile material (Plutonium 239), without triggering nuclear chain reaction or explosion. In other words, subcritical tests are not a violation of the CTBT. But Mr. Trump, in another interview, clearly said, ‘We are going to test nuclear weapons like other countries do”.
Devastating effects
The 1963 Partial Test Ban Treaty, signed by the Soviet Union, the U.S. and the U.K., banned all nuclear test detonations in the atmosphere, outer space and underwater. Since then most tests were conducted underground. (Now, CTBT bans all tests, including underground detonations). Even subterranean tests, experts say, could cause devastating environmental damages, including total destruction of ecosystems at test sites and contamination of soil, air and water. Radioactive contamination could affect vast areas for hundreds of years.
If the U.S. breaks the moratorium and starts testing weapons, it could cause a domino effect on other nuclear powers. There were reports that China had made preparations at Lop Nur, where Mao detonated China’s first bomb in 1964, in case it decides to resume testing. For now, China has called on the U.S. to maintain the moratorium. Russia was unambiguous in its reaction. “If they begin testing, naturally we will do the same,” Russia’s Security Council chief Sergey Shoygu said on October 31, 2025. If the U.S. and Russia resume tests, China, which hasn’t carried out as many tests as its nuclear peers, could do the same. And if China does it, India will come under internal pressure to start testing its weapons. Then Pakistan may not stand out. A new phase of nuclear arms race would begin, with long-term consequences for humanity.
Published – November 06, 2025 11:48 am IST
