John Moolenaar, chairman of the U.S. House Select Committee on Strategic Competition between the United States and the Chinese Communist Party, has written to Secretary of State Marco Rubio urging the Trump administration to pay close attention to the recent warming of relations between South Korea and China.
In the letter, sent a day earlier, Moolenaar called for "heightened vigilance" over the relationship, citing deepening ties between the two countries' leaders, South Korean semiconductor investment in China and what he described as unfair treatment of U.S. companies in South Korea compared with Chinese firms, Reuters reported on the 30th.
Moolenaar said the pace of exchanges between the two leaders was unprecedented, noting that Chinese President Xi Jinping visited South Korea last November for the first time in 11 years and that President Lee Jae-myung traveled to China early this year for the first time in six years.
He described South Korea as a "key ally" of the United States. But he said a "widening gap" between Seoul and Washington was especially concerning, arguing that South Korea had effectively ruled out supporting a regional response to a Chinese attack on Taiwan. Moolenaar also referred to a remark Lee made during the 2024 presidential race, when he asked what the Taiwan Strait had to do with South Korea.
On technology and supply chains, he pointed to South Korean chip investment in China as a risk factor. Moolenaar argued that South Korean production facilities in China could increase the chances of exposing critical U.S. semiconductor supply chains to Chinese influence.
Citing Samsung Electronics' chip plant in Xi'an and SK hynix's operations in Wuxi and Dalian, he said Beijing could use those facilities as leverage to pressure chip production by U.S. allies.
He also said South Korean rules governing Chinese e-commerce platforms such as Alibaba's AliExpress and Temu were looser than those applied to U.S. companies including Coupang in areas such as data privacy, consumer protection and cybersecurity. Moolenaar has asked the State Department for a briefing on the changes in Seoul-Beijing relations by the 31st of next month.
Reuters said the letter came as relations between Seoul and Washington have been strained, noting that President Donald Trump has recently criticized South Korea sharply in public. Trump has voiced frustration by arguing that South Korea has not been active enough on issues related to the war with Iran, including the Strait of Hormuz.
Asked by Reuters to comment on the letter, South Korea's foreign ministry said it could not comment specifically, but added that the alliance with the United States is the foundation of the country's foreign policy and that the two sides continue to develop the partnership across many areas. The ministry also stressed that South Korean regulators treat all companies operating in the country fairly, according to Reuters.
