President Donald Trump and South Korea President Lee Jae Myung shake hands during a meeting in the Oval Office of the White House in Washington on August 25. Lee asked at the U.S.-Korea Summit on Wednesday about building a nuclear submarine. File Photo by Al Drago/UPI | License Photo
“President Trump, I ask you to make a bold decision so that South Korea can receive fuel for nuclear-powered submarines.”
When President Lee Jae Myung suddenly uttered those words during the second U.S.-Korea summit in Gyeongju on Wednesday, many Koreans watching on live television gasped.
What startled them even more than the bold ask was his reasoning. Lee explained that “diesel-powered submarines have limited underwater endurance, restricting our ability to track North Korean and Chinese vessels,” and that if South Korea deployed nuclear-powered submarines, “it would also substantially reduce the operational burden on U.S. forces.”
It was, by any standard, a statement fraught with risk — a security issue so sensitive that every word could be seized upon as a diplomatic provocation. Yet, Lee voiced it publicly before an audience that included not only his own citizens, but also the entire watching world.
Among those “citizens” were progressives critical of the United States, and within that “world” was China itself.
No hesitation
Even so, Lee showed no hesitation. His tone revealed a determined will to press Trump for what he called a “bold decision.” It was a perilous remark — one that seemed to disregard how his own supporters or his longtime partners in Beijing might interpret it.
Yet, he nonetheless requested, in full view of the public, that Washington supply nuclear-submarine fuel so that South Korea could track Chinese submarines for extended periods underwater.
Anyone can understand why the remark appeared dangerous once Lee’s position is taken into account. Lee had invited President Xi Jinping of China to South Korea as a state guest for the Gyeongju APEC Summit — the first Korea-China summit in 11 years.
And just two days before that meeting, he openly sided with Washington, now in strategic confrontation with Beijing, by calling for U.S. assistance on nuclear-powered submarines. What, one wonders, would Xi have thought if he had heard those words?
A calculated gamble
Still, Lee’s statement was almost certainly not a spontaneous remark. It bore every sign of careful calculation. Otherwise, he could not have spoken with such conviction — and on a domain of the alliance that no previous progressive leader had dared to touch.
From the start of his presidency, Lee has signaled that his foreign policy compass is anchored in realism. In his inaugural address, he vowed to strengthen the U.S.-Korea alliance, deepen trilateral cooperation with Japan and pursue relations with neighboring powers “from the standpoint of national interest and pragmatism.”
Skeptics — both in Seoul and Washington — doubted his sincerity. But Lee has stayed the course, even flipping the long-held progressive formula of “security with America, economy with China” into a new doctrine: “security with America, economy with America.”
During his August visit to Washington, Lee declared, “It’s true that South Korea once relied on the U.S. for security and China for the economy, but that posture is no longer sustainable.”
That statement came one day after Chinese Ambassador Dai Bing warned that Seoul must demonstrate “the wisdom and ability to maintain balanced diplomacy” between Washington and Beijing.
Lee’s response — firm and immediate — left little doubt about where he stood. In an era of escalating U.S.-China rivalry, his position made one thing clear: Seoul’s ambiguity was over.
The alliance redefined
Seen in that light, Lee’s nuclear-submarine request was a logical extension of his declared vision — a reaffirmation of alliance solidarity through tangible deterrence. By signaling a willingness to patrol not only North Korean but potentially Chinese waters with U.S. cooperation, Lee effectively fixed South Korea’s coordinates alongside Washington, not Beijing.
He went further still. During the summit, Lee proposed building multiple nuclear-powered submarines armed with conventional weapons, with South Korea covering the entire cost.
The United States, he said, would not need to spend a penny. For Trump, who has promoted an Indo-Pacific containment strategy against China, such an offer was pure strategic gold. Some analysts even suggested that Lee’s surprise proposal helped break an impasse in the subsequent U.S.-Korea tariff negotiations, which were resolved far more smoothly than expected.
The urgency of Lee’s concern is not misplaced. The Yellow Sea (West Sea) has grown perilous since China’s 2010 declaration of the area as its “internal waters.”
Beijing has since deployed more than 70% of its maritime buoys near choke points to obstruct allied naval access. Since 2022, it has erected unapproved metal structures named Shenlan 1 and 2 inside the provisional maritime zone, blocking Korean coast-guard vessels from approaching.
In September, a Chinese warship even chased off a South Korean survey boat. In such volatile waters, threats lurk not only above but beneath the surface, making Lee’s call for undersea endurance sound less like provocation and more like precaution.
Trump’s response was swift. Within 24 hours, he posted on Truth Social, announcing that the United States had approved South Korea’s construction of nuclear-powered submarines “to be built at the Philly Shipyard.” Reuters noted that this was “technology previously shared only with Britain in the 1950s — and not even with Australia.”
The China question
Now all eyes turn to China. As Xi Jinping arrives in Seoul for a long-delayed state visit, friction seems inevitable. Beijing is expected to raise the nuclear-submarine issue, and possibly Lee’s “security-and-economy-with-America” remarks, as provocations. Yet, it is hard to imagine that Lee made his request without a contingency plan in place.
South Korea, after all, recognizes China as a vital partner. Since normalizing ties in 1992, Seoul and Beijing have upgraded relations through successive frameworks — from “friendly cooperation” to “strategic cooperative partnership.”
Bilateral trade surpassed $300 billion in 2021, making China Korea’s second-largest trading partner after the United States. Korean conglomerates and small and medium-sized enterprises are investing heavily in high-tech and new-energy sectors, underpinned by free-trade and investment-protection agreements.
Still, obstacles remain — from Beijing’s lingering “Hallyu ban” on Korean cultural content after the deployment of the THAAD anti-missile system in 2017 to deep-seated distrust over regional security.
Those tensions help explain why the two neighbors have not held a full summit in more than a decade. As Lee meets Xi in the coming days, Koreans hope he will negotiate confidently, guided by national interest and diplomatic principle.
No matter the outcome, one reality is now unmistakable: Lee Jae Myung has left the shores of strategic ambiguity. He has crossed the Rubicon.
Nohsok Choi is the former chief editor of the Kyunghyang Shinmun and former Paris correspondent. He currently serves as president of the Kyunghyang Shinmun Alumni Association, president of the Korean Media & Culture Forum and CEO of the YouTube channel One World TV.
