Today, the global nuclear order offers a curious contradiction — since the bombing of Hiroshima and Nagasaki in August 1945, nuclear weapons have not been used during the last 80 years. The global nuclear arsenals have come down from a high of 65,000 bombs in late 1970s to less than 12,500 today. And, despite concerns in the 1960s that by 1980, there may be at least two dozen states with nuclear weapons, the total today remains nine — five (the United States, Russia, the United Kingdom, France and China) are permanent members of the United Nations Security Council who had tested before the Nuclear Non-Proliferation Treaty (NPT) came into being while four more developed their nuclear arsenals later (Israel, Pakistan, India and North Korea).

Looking back, these would seem to be impressive achievements but nobody is celebrating. In fact, the prevailing sentiment is that the global nuclear order is under strain and the recent announcements by U.S. President Donald Trump may weaken all three elements of the global nuclear order.

Resumption of ‘nuclear tests’

On October 30, 2025, on his way to a meeting with China’s President Xi Jinping in Busan, Mr. Trump announced on Truth Social, “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 added, “Russia is second, China is a distant third, but will be even within 5 years.”

While it was clear that the message was directed at Russia and China, it was unclear whether Mr. Trump was referring to ‘nuclear explosive testing’ or the testing of nuclear weapon systems. Second, the nuclear labs (Los Alamos, Lawrence Livermore, and Sandia) and the Nevada testing facilities fall under the Department of Energy and not the Department of War.

It is no secret that China, Russia, and the U.S. are designing and developing new nuclear weapons. In late October, Russia tested a nuclear-powered cruise missile (Burevestnik) that travelled 14,000 kilometres, following a week later, with a test of an underwater nuclear-powered torpedo (Poseidon). China has been testing hypersonic missiles and, in 2021, tested a nuclear capable hypersonic glide vehicle carried on a rocket, capable of orbiting the earth before approaching its target from an unexpected direction that was passed off as a satellite launcher.

The U.S. is producing new warheads — a variable yield B61-13 gravity bomb, a low yield W76-2 warhead for the Trident II D-5 missile, while working on a new nuclear armed submarine launched cruise missile.

Yet, they have refrained from explosive testing. Russia’s last explosive test was in 1990 while the U.S. declared a moratorium on tests in 1992. In 1993, the U.S. created a Stockpile Stewardship and Management Programme under the National Nuclear Security Administration to work on warhead modernisation, life extension and development of new safety protocols in warhead design. U.S. President Bill Clinton also took the lead in pushing negotiations in Geneva for a Comprehensive Test Ban Treaty (CTBT). China and France concluded their tests in 1996, six months before the negotiations ended.

Why the CTBT lacks a definition

Twenty-nine years later, the CTBT has not entered into force despite 187 countries signing it. Among the necessary ratifications, the U.S., China, Israel, Egypt, and Iran have not done so, Russia did and withdrew its ratification in 2023, and India, Pakistan and North Korea have neither signed nor ratified it. India and Pakistan tested in 1998 and have since observed a voluntary moratorium, and North Korea conducted six tests between 2006 and 2017. Given today’s geopolitics, the prospects for the CTBT entering into force appear bleak.

Second, the CTBT obliges states “not to carry out any nuclear weapon test explosion or any other nuclear explosion”. The U.S. was opposed to defining the terms, and instead, worked out private understandings with Russia and China on ‘zero-yield-tests’; this permitted hydro-nuclear tests that do not produce a self-sustaining supercritical chain reaction.

The U.S. had conducted over a thousand nuclear tests and Russia 727 tests, giving them an adequate data base. China, with only 47 tests, also went along with this understanding. Thus, the CTBT delegitimised only nuclear-explosive testing, not nuclear weapons, the reason why India never joined it.

In 2019-20, the U.S. State Department assessed that Russia and China “may have conducted low yield nuclear tests in a manner inconsistent with the U.S. zero-yield standard” though this was negated by the CTBT organisation that declared that their monitoring network with over 300 monitoring stations spread over 89 countries had not detected any inconsistent activity.

In a TV interview on November 2, Mr. Trump doubled down on resuming nuclear testing, this time including Pakistan and North Korea among the countries testing. A clarification came the same day from U.S. Secretary of Energy Chris Wright on Fox News, calling the U.S. tests ‘systems-tests’. “These are not nuclear explosions. These are what we call noncritical explosions,” he said. However, Mr. Trump’s intention remains unclear.

The new low-yield warheads being designed make them more usable and the new systems (hypersonics, cruise and unmanned systems) are dual capable systems, leading to renewed research for missile defences such as the U.S. ‘golden dome’. Meanwhile, doctrinal changes are being considered to cope with new technological developments in cyber and space domains. This raises doubts about the nuclear taboo in the coming decades.

The sole surviving U.S.-Russia arms control agreement, the New Strategic Arms Reduction Treaty (New START) that limits the U.S. and Russian strategic forces to 700 launchers and 1,550 warheads is due to expire on February 4, 2026 with no prospects of any talks on the horizon. China is not a party to any arms control and its nuclear arsenal that had remained below 300, is undergoing a rapid expansion, estimated at 600 today, and likely to exceed 1,000 by 2030. An incipient nuclear arms race was already underway; a resumption of explosive testing will just take the lid off.

Russia and China have denied Mr. Trump’s allegations regarding clandestine tests, but will follow if the U.S. resumes explosive testing. China will be the biggest beneficiary because with only 47 tests (compared to over 1,000 by the U.S.), resumed tests will help it to validate new designs and accumulate data.

India has been observing a voluntary moratorium. But if explosive testing resumes, India will certainly resume testing to validate its boosted fission and thermonuclear designs, tested only once in 1998. Undoubtedly, Pakistan will follow but given its growing strategic linkages with China witnessed during Operation Sindoor, this need hardly adds to India’s concerns.

Though the CTBT is not in force, it did create a norm. But a resumption of explosive testing will lead to its demise. It will also tempt the nuclear wannabes to follow and mark the unravelling of the NPT led non-proliferation regime.

The taboo against use must remain intact

The U.S. has been the most significant player in shaping the global nuclear order. It would be ironic if Mr. Trump’s actions now become the catalyst for its demise. The reality is that the present global nuclear order was shaped by the geopolitics of the 20th century. The challenge today is to craft a new nuclear order that reflects the fractured geopolitics of the 21st century while ensuring that the taboo against their use remains intact.

The United Nations Secretary General has cautioned that “current nuclear risks are already alarmingly high” and urged nations “to avoid all actions that could lead to miscalculation or escalation with catastrophic consequences.” But is anyone listening?

Rakesh Sood is a former diplomat and is currently Distinguished Fellow at the Council for Strategic and Defense Research (CSDR)

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