S. Korea’s New President: Is Lee’s desire for ‘Close Cooperation with Japan, U.S.’ Genuine?

Editorial

16:15 JST, June 5, 2025

Warfare has not ceased in the world and the security environment in East Asia is becoming increasingly severe. It is hoped that South Korea’s new president will emphasize close cooperation with Japan and the United States and implement a foreign and security policy that is in line with reality.

Lee Jae-myung, the former leader of the left-leaning Democratic Party, the largest opposition party, was elected in the South Korean presidential election held in the wake of the removal of former President Yoon Suk Yeol. In his inaugural address on June 4, Lee said that he will “serve all as the president for everyone.”

The new president must bring under control the turmoil in South Korea that has continued for six months since Yoon declared martial law in December last year, and he needs to get the country’s politics back on the right track.

The left-wing forces regained power from the conservatives for the first time in three years. The leftists also hold a majority in the National Assembly. Taking advantage of the favorable political situation, Lee should work to resolve issues that are of great concern to the public, such as high prices, the high tariff policy of U.S. President Donald Trump’s administration and South Korea’s rapidly aging population and the birth rate remaining low.

Lee is in an unusual position as he is a defendant in multiple criminal trials, including for violation of the public offices election law. He begins his administration in an unstable manner.

An urgent issue for the new administration is how to deal with North Korea, China and other countries.

In addition to its nuclear and missile development programs, North Korea has been participating in Russia’s aggression against Ukraine by deploying its troops and providing weapons to Russia, spreading the war in Europe to Asia. China is continuing its aggressive maritime expansion in the East China Sea and the South China Sea.

It is noteworthy that, in light of this international situation, Lee has expressed his intention to fundamentally maintain the Yoon administration’s policy direction, which attached importance to trilateral cooperation between Japan, the United States and South Korea based on the U.S.-South Korea alliance.

On the other hand, in terms of his policy toward North Korea, Lee has stated that “dialogue and cooperation are necessary,” expressing his willingness to improve relations with North Korea. However, at the end of 2023, North Korea positioned South Korea as a “hostile state” and abandoned its policy of the peaceful unification of North Korea and South Korea. Reconciliation with North Korea does not seem to be a policy that conforms to the actual situation.

Japan is most concerned about Lee’s policy toward Japan.

Relations between Japan and South Korea improved significantly as the Yoon administration worked out a solution to the issue of lawsuits regarding former wartime requisitioned workers from the Korean Peninsula, which had been the biggest pending issue between the two countries. Lee has harshly criticized this as a “diplomacy of humiliation toward Japan.”

Throughout his presidential election campaign, Lee positioned Japan as an “important, cooperative partner” and emphasized a positive attitude to promote economic cooperation and other measures. However, concerns cannot be dispelled that he may strengthen a tough stance toward Japan again in the future.

With the Trump administration’s disregard for alliances and international cooperation, stable relations and solidarity between Japan and South Korea are essential for multilateral cooperation, including that between Japan, the United States and South Korea, to function. Lee should recognize the weight of his responsibility.

(From The Yomiuri Shimbun, June 5, 2025)