Donald Trump (File photo)The TOI correspondent from Washington: US President Donald Trump on Sunday said Pakistan, North Korea, China, and Russia were conducting secret underground nuclear tests to assert that the U.S too would resume nuclear tests. In a CBS 60 minutes interview telecast Sunday night, Trump insisted that other countries, including Pakistan, were conducting underground tests, rejecting the questioner’s contention that countries like Russia were only testing delivery systems like missiles without nuclear payload.Defence Experts Offer Stark Warnings After Donald Trump Claims Pakistan Is Conducting Nuclear Tests“No, we're going to test because they test and others test. And certainly North Korea's been testing. Pakistan's been testing,” Trump maintained, adding, “You don't necessarily know where they're testing. They test way underground where people don't know exactly what's happening with the test.”According to Washington’s own account under previous administrations, all five formally recognized nuclear powers (P-5), including the US, Russia, and China have observed a moratorium on explosive nuclear testing for more than 25 years. Russia's last test was in 1990 (as the Soviet Union), and China's last test was in 1996.India too, as a de facto nuclear power, announced a voluntary and unilateral moratorium on nuclear testing after its Shakti tests in May 1998 even though it is not legally obligated to do so since it is not a signatory to the Comprehensive Test Ban Treaty (CTBT). North Korea is the only country that has conducted nuclear weapon tests (explosions) in the 21st century.However, US government reports have occasionally expressed suspicion that Russia and China may have conducted very low-yield or "sub-critical" tests that could technically violate the "zero-yield" standard of the testing moratorium, but they have not provided definitive public proof of full-scale nuclear explosions. Experts say low-yield tests are hard to distinguish from sub-critical tests, which are generally considered permissible under the CTBT. Trump appeared to be suggesting that countries are conducting such low yield, sub-critical tests, saying “people don't know exactly what's happening with the test…you feel a little bit of a vibration.”Energy Secretary Chris Wright later brought some clarity to Trump’s announcement, tempering the President’s remarks to say the US would be focusing on system tests or what are called noncritical explosions. “These are not nuclear explosions. These are what we call noncritical explosions. So you’re testing all the other parts of a nuclear weapon,” he told Fox News. This is a routine and ongoing practice for all nuclear powers. Russia recently said it had successfully tested a nuclear-powered cruise missile, the Burevestnik, and a large torpedo, the Poseidon, which are nuclear-capable weapons systems. Wright suggested Trump had greenlighted such systems testing following Russia’s announcement to reassure Americans that the U.S will do whatever it takes to remain the pre-eminent world power. In fact, Trump appeared not to know that the Department of Energy, specifically the National Nuclear Security Administration (NNSA) under it, manages the nation's nuclear arsenal and test sites, since he directed his order to resume nuclear testing “immediately” and “on an equal basis” with Russia and China to the Pentagon. Non-proliferation experts were mystified by Trump's announcement, calling it incoherent and foolish. "By foolishly announcing his intention resume nuclear testing, Trump will trigger strong public opposition in Nevada, from all US allies, and it could trigger a chain reaction of nuclear testing by US adversaries, and blow apart the nuclear Nonproliferation Treaty," Darryl Kimball, Director of Arms Control Association, wrote on X. He said Trump's post is not clear about whether he is talking about n-explosive testing (which the NNSA would do) or flight testing of n-capable missiles (which the DoD does). In either case, the announcement seemed to go against Trump's anathema towards nuclear weapons. Although he has frequently boasted of the potency of US nuclear arsenal and his role in maintaining its primacy, Trump has often said he abhors nuclear weapons for their destructive power and wishes the world could get rid of them.