Alarmed by Trump, South Korea mulls Japan-style nuclear option

Prominent voices seek capacity to reprocess spent nuclear fuel or enrich uranium and be able potentially to make bombs.

ASIA TIMES, by Daniel SneiderMarch 15, 2025

……………………………………………………………………………………………………………………………………………… The most striking evidence of South Korean alarm over the treatment of allies is the widening discussion of the need to have an independent nuclear arms capability. Conservatives have long advocated that option, but the debate has now moved into progressive circles where prominent voices are calling for South Korea to develop nuclear latency – the capacity to reprocess spent nuclear fuel or enrich uranium to be able to potentially possess fissile material for making bombs.

The Japanese model?

For now, South Korea hopes it can follow the path set by Japanese Prime Minister Shigeru Ishiba and offer Trump concessions ranging from trade, supply chain investment, and cooperation on shipbuilding to promoting South Korea’s role as an asset in a confrontation against China.

At the moment, South Korea does not have an effective government, pending the imminent decision of the Constitutional Court on the impeachment of South Korean President Yoon Suk Yeol. But whatever follows, the South Korean president will have to deal with Trump.

Assemblyman Wi believes the best they can hope for is a smooth and non-confrontational meeting modeled on that of Ishiba, which yielded a joint statement that reaffirmed the US-Japan alliance along the lines of previous statements with the Joe Biden administration.

………………………………………………………………………………….. I think President Trump thinks North Korea is unfinished business left over from the first Trump administration. We have to prepare for the worst.”

Nuclear latency

“The worst” includes the withdrawal of United States Forces Korea (USFK) from South Korea and a withholding of the US nuclear umbrella.

Regardless of how important the U.S.-ROK alliance is now, “there may come a time when it is difficult to rely on the US for our security,” former Minister of Foreign Affairs Yoon Young-kwan wrote in an op-ed published this month. “In preparation for that time, we should strengthen our national defense capabilities, including potential nuclear capabilities, and prepare to handle the deterrence of North Korea with our own strength.”

Progressives are more reticent to endorse nuclear weapons outright, but some have thrown their weight behind nuclear latency – a conscious imitation of the model pursued by Japan to have a full fuel cycle capability. South Korea could, theoretically, reprocess the spent fuel from its power reactors to extract bomb-grade plutonium or, alternatively, have the capacity to enrich uranium, potentially up to bomb-grade levels.

South Korea has long sought to revise the so-called 123 agreement for nuclear cooperation with the United States, which has restricted its ability to have a full fuel cycle. The agreement was only recently reaffirmed, in January at the close of the Biden administration.

In an important column published on March 4 in the progressive newspaper Kyunghyang Shinmun, former Minister of Unification Lee Jong-seok, another close advisor to presidential aspirant Lee Jae-myung, argued that nuclear latency can be achieved within the framework of the Nuclear Non-Proliferation Treaty and with the consent of the United States.

“China, Russia and North Korea, our neighboring countries, are nuclear weapon states, and Japan has already demonstrated its potential,” Lee wrote. “In this situation, it is rather unnatural that South Korea, a nuclear power, cannot reprocess or enrich uranium due to the restrictions of the Korea-US Nuclear Energy Agreement.”

Others in Seoul advocate defecting from the 123 agreement if the United States reduces USFK forces on the peninsula, says Kim Joon-hyung, a Rebuilding Korea Party lawmaker and former senior diplomat.

Kim is a critic of the U.S. alliance but is personally opposed to nuclear latency. “I don’t agree with nuclear proliferation,” he said. “Even if we have nuclear weapons, I don’t think we have security. Small conflicts may become more common. The Korean Peninsula is too small – high tech conventional weapons are enough. Japan will go nuclear and relations with China and Russia will worsen.”

Others are concerned about the isolation that South Korea could experience if it goes down this road. Cho Hyun, a former senior diplomat and progressive foreign policy advisor, helped negotiate the 123 agreement during the Bill Clinton administration. “The right wing thinks we should have our own nuclear development,” Cho told me in Seoul. “We don’t think it is realistic. Some progressives want to request the US for full fuel cycle like Japan. I am against this.”

As the nuclear latency argument rapidly gains support among progressive circles, revising the 123 agreement may become a bargaining chip for South Korea in negotiations with the Trump administration.

At least some inside the administration, though likely not Trump-appointed officials, have become aware of this, prompting media reports that the U.S. Department of Energy is considering labeling South Korea a “sensitive country,” a designation for countries who might be considering going nuclear.

For South Korea, this may only be the start of many shocks to come.

Daniel C. Sneider is a non-resident distinguished fellow at the Korea Economic Institute of America and a lecturer in East Asian studies at Stanford University. https://asiatimes.com/2025/03/alarmed-by-trump-south-korea-mulls-japan-style-nuclear-latency/#