In a dramatic series of moves that could reshape the global nuclear landscape, US President Donald Trump has simultaneously approved South Korea’s entry into the nuclear submarine club and declared the resumption of US nuclear weapons testing, a combination that signals a new phase in Washington’s strategic posture.
Trump made the first announcement during his meeting with South Korean President Lee Jae Myung in Gyeongju on Wednesday (October 29, 2025), ahead of the Asia-Pacific Economic Cooperation (APEC) summit. A day later, he followed it up with an online post which said the US would restart testing its nuclear arsenal “on an equal basis” with rivals.
Taken together, the two moves highlight what is being viewed as Trump’s “dual nuclear doctrine”, one that aims to reassert US nuclear dominance and shore up key allies in a rapidly polarising Indo-Pacific.
South Korea’s nuclear submarine approval: Why is it a game-changer?
An interesting thing to note here is that for several decades, the United States has opposed South Korea’s push for nuclear-powered submarines, citing non-proliferation concerns and fears of regional escalation. Trump’s decision overturns that long-held stance. “South Korea will be building its Nuclear Powered Submarine in the Philadelphia Shipyards, right here in the good ol’ U.S.A. Shipbuilding in our Country will soon be making a BIG COMEBACK,” Trump declared on Truth Social.
The submarine will reportedly be built at Philadelphia Shipyards, where South Korean firms have recently increased investment. If executed, the project would make South Korea the seventh nation capable of operating nuclear-powered submarines, a leap that dramatically enhances its deterrence against North Korea.
Trump also announced Seoul’s agreement to purchase large quantities of US oil and gas, tying economic and defence cooperation together. However, questions remain – when will the submarine project begin? Who will supply the propulsion technology?
US return to nuclear testing: Why President Trump announced so?
Just an hour before his expected meeting with Chinese President Xi Jinping, Trump unleashed another headline-making post on Truth Social, explaining the motive behind his decision to restart the testing of nuclear weapons. “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.”
This followed Russia’s recent nuclear “superweapon” tests, including an underwater drone designed to generate massive tsunamis, and President Vladimir Putin’s boast of an “unlimited-range” nuclear-powered missile.
On the surface, US President Trump’s statement appears to be a direct response to Moscow’s growing nuclear assertiveness and China’s quiet nuclear expansion. He has also repeatedly cited North Korea’s continued missile launches, including a cruise missile test just before his visit to Seoul.
What could be the strategic implications of US nuclear testing?
If carried out, the tests would be the first since 1992, breaking more than three decades of US compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), though Washington never formally ratified it. Russia, which withdrew its ratification in 2023, has already indicated it will mirror any US moves.
China, on the other hand, remains a signatory but hasn’t conducted a test since 1996. Analysts are of the view that restarting nuclear testing could trigger a global arms race and undermine decades of nuclear restraint. Rep. Dina Titus has already vowed to introduce legislation blocking Trump’s plan, citing the environmental and diplomatic fallout.
Is Trump signalling a return to arms racing?
Despite the confrontational tone of his posts, Trump later told reporters aboard Air Force One that his ultimate goal was “de-escalation.” “I think de-escalation — they would call it denuclearization — would be a tremendous thing,” he said. “We are actually talking to Russia about that, and China would be added if we do something.”
But the parallel announcements – a nuclear submarine for Seoul and renewed US weapons tests – suggest that Washington under Trump is prioritising visible nuclear capability over diplomatic restraint.
Meanwhile, Iran has condemned Trump’s decision, with its foreign minister Abbas Araghchi calling US plans to resume nuclear testing “regressive and irresponsible”. “A nuclear-armed bully is resuming testing of atomic weapons. The same bully has been demonizing Iran’s peaceful nuclear program,” Araghchi said in a post on social media.
“The (US) announcement of a resumption of nuclear tests is a regressive and irresponsible move and a serious threat to international peace and security,” he added.