A bold reconsideration of an age-old idea: the Korea–Japan undersea tunnel has repeatedly resurfaced in Korean politics, this time entangled in a widening Unification Church scandal over illicit funding to senior politicians. The concept first surfaced in 1981 and has long been touted as a major national project, even though its economic viability and technical feasibility have repeatedly been questioned.
New findings released by a special counsel on December 10 allege that former Oceans Minister Chun Jae-soo received political funds and luxury gifts from the Unification Church in exchange for pushing the tunnel initiative. Investigators say Yun Young-ho, once the church’s global headquarters chief, identified Chun as one of five prominent politicians from both major parties who allegedly benefited from church support between 2018 and 2020. Yun is said to have claimed that Chun accepted a Bulgari watch and 20 million won (about $13,500) in cash linked specifically to lobbying for the tunnel during the Moon Jae-in administration. Chun has denied the accusations as false.
A long-standing church project with broad echoes in politics
The Korea–Japan undersea tunnel has been raised by various Korean leaders for decades. What’s less widely known is that the notion was publicly introduced at a Unification Church event more than 40 years ago and has since been presented as a central aim of the movement. In 1981, Moon Sun-myung, the church’s founder, introduced the “International Peace Expressway Initiative,” which envisioned an enormous network connecting Tokyo to London and New York via Seoul, with a tunnel serving as the Korea–Japan link at its core.
Within Unification Church doctrine, Moon described Korea as the “father country” and Japan as the “mother country,” with Korea labeled the “Adam Country” as the birthplace of the church’s messiah. He argued that the two nations must be physically connected to birth a “new civilization,” and he asserted that Japan owed moral restitution for its colonial rule in order to support funding for the tunnel—an idea that helped sustain fundraising among Japanese followers for many years.
A mix of hopes, hurdles, and headlines
The tunnel would connect Busan or Geoje Island in Korea with Karatsu on Japan’s Kyushu Island. The church is said to have acquired land in Karatsu’s northern coast and even excavated a small exploratory tunnel, with church members in Japan continuing to visit the site.
Politically, the tunnel has appeared at various moments: Roh Tae-woo publicly raised the idea during a 1990 visit to Japan; later presidents Kim Dae-jung and Roh Moo-hyun mentioned it in discussions about Korea–Japan economic cooperation. In 2021, Kim Jong-in, then head of the People Power Party’s emergency committee, revived the proposal. Since 2003, Busan mayors from across the political spectrum have treated it as one of the city’s major projects. Reports suggest the Unification Church approached lawmakers with the tunnel plan in 2022 just before a presidential election.
Yet the project has never moved forward, largely due to enormous costs and weak economic prospects. The Busan Development Institute estimated in 2016 that a roughly 200-kilometer tunnel would cost about 116 trillion won. A 2010 assessment projected potential production benefits of 54.53 trillion won and added value of 19.80 trillion won, along with roughly 450,000 jobs, but deemed the undertaking unfeasible because of the extreme construction challenges posed by water depths up to 210 meters.
Experts also cite historical cautions: the Channel Tunnel between the United Kingdom and France, though only 50 kilometers long with a 20-kilometer undersea portion, did not become profitable until 2008, fourteen years after it opened in 1994.
Why the tunnel resurfaced in investigations
Public attention intensified after the arrest of Yun Young-ho on September 23 for allegedly delivering 100 million won to People Power Party lawmaker Kweon Seong-dong in 2022, purportedly in exchange for various political favors including the tunnel should President Yoon Suk Yeol win the election. Investigations widened, leading to the detention of Unification Church leader Han Hak-ja. Yun cooperated with investigators, claiming that Oceans Minister Chun received illicit funds from the church in exchange for advancing the tunnel project. The special counsel sought a four-year sentence for Yun.
Yun reportedly told investigators that Chun Jae-soo received bribes at the Unification Church’s Cheonjunggung headquarters between 2018 and 2020. Chun has maintained his innocence and resigned on December 11.
The allegations tying liberal figures to the matter emerged as part of the special counsel’s broader inquiry into the church’s connections with political parties, including the main opposition People Power Party. In response, President Lee ordered a comprehensive investigation into anyone suspected of illegal funding from the Unification Church, regardless of political affiliation, on December 10.
Would you support or oppose reviving a project with such a controversial history and questionable economics? How should lawmakers balance national ambition with transparency and due diligence when proposals come tangled with political and religious influence? Share your thoughts in the comments.
