In the Upper House election on July 20—seen as decisive for the fate of the Ishiba administration—the Liberal Democratic Party (LDP) suffered a crushing defeat, placing the Ishiba Cabinet on the brink of resignation. Having failed to secure a majority for the LDP–Komeito coalition across both houses, the Ishiba Cabinet now faces the unprecedented situation of losing a majority in both the House of Representatives and the House of Councillors. Although many expected Prime Minister Ishiba to step down immediately after the electoral debacle, he instead expressed his intent to stay on. Within Japan, heated debate over whether the cabinet should resign has created an unavoidable political turmoil. Meanwhile, the LDP’s defeat, combined with the underperformance of the main opposition Constitutional Democratic Party, and the advances of alternative forces such as the Democratic Party for the People and the Sanseitō, signal the collapse of the LDP-dominated system and point to the possibility of a structural realignment in Japanese politics. Rising uncertainty and structural change in Japan’s political landscape are also highly likely to affect Korea–Japan relations. Thus, South Korea should take more proactive measures to stabilize bilateral ties.

First, the South Korea–Japan summit scheduled for August 23, alongside the presidential visit to Japan, must go beyond ceremonial aspects of leadership change and include concrete steps to stabilize bilateral relations and reinforce trilateral cooperation with the United States. Second, with the collapse of the LDP’s dominance and the potential restructuring of Japan’s political order in mind, South Korea should establish communication channels not only with the LDP but also with other major political parties. Third, given the shifts in Japan’s immigration policies revealed in this election, Seoul should prepare diplomatic and administrative responses to prevent any harm to Korean nationals.

This article is an English Summary of Asan Issue Brief (2025-24).

(‘2025 참의원 선거 이후 혼돈의 일본 정치:일본 정치질서의 재편이 한일관계에 미치는 영향’)