On September 7, Japanese Prime Minister Shigeru Ishiba announced that he would step down in response to mounting pressure within his Liberal Democratic Party (LDP). Since Ishiba took office in October 2024, the LDP has suffered defeats in two separate national elections that resulted in the ruling coalition losing its majority in both houses of parliament for the first time in the last 70 years. Ishiba’s resignation comes at a time when Japan is facing many challenges at home and abroad, including inflation, a weak yen, U.S. tariffs, and security threats from China, North Korea, and Russia. Several LDP leaders have been floated as potential candidates to succeed him in a contest that will be scheduled soon ahead of a new parliamentary session this fall. This hasty political transition could prove a test of Japan’s mettle as it confronts an increasingly unstable domestic and international environment.
Q1: Why did Ishiba decide to resign now?
A1: Ishiba has encountered challenges and criticism since the start of his tenure as prime minister in October 2024. Long known as an outsider within the LDP, Ishiba has dealt continuously with internal divisions within his own party, as well as an increasingly influential political opposition. Amid ongoing public discontent over financial scandals involving the LDP, he decided to call a snap election shortly after taking office in October, resulting in the LDP and its coalition partner Komeito losing their majority in the powerful Lower House of the Japanese Diet. During the subsequent months, Ishiba struggled to meaningfully address the public’s concerns about corruption and difficult economic conditions, particularly inflation and rising prices for staples such as rice. Despite a successful initial summit with President Donald Trump in February, Ishiba’s term in office has also been dominated by tense negotiations with the United States over tariffs and an increasingly challenging regional security environment, evidenced most recently by the joint appearance of Xi Jinping, Vladimir Putin, and Kim Jong-un in Beijing.
Pressure for Ishiba to resign intensified greatly after the LDP-Komeito coalition lost its majority in the July 20 Upper House election. Immediately after the defeat, Ishiba maintained that he intended to stay in office to conclude negotiations over the U.S.-Japan trade deal. After the deal was announced on July 22, Ishiba continued to insist that continuity in leadership was necessary to deal with foreign and domestic policy challenges, and he won some support from the Japanese public for his perseverance. However, calls for his resignation have continued to escalate within the LDP over recent weeks, and the decision last week by key LDP figure Secretary-General Hiroshi Moriyama to step down further weakened Ishiba’s position. While the prime minister insisted on staying, party members sought an early leadership election, which would have effectively forced him to step down if the motion were approved. On the eve of a September 8 vote to decide on the leadership election, and with early counts suggesting he was likely to lose, Ishiba announced his resignation. In his comments to the press on September 7, Ishiba said that he decided to resign not because of the impending vote but rather because he had succeeded in ironing out key details of the U.S.-Japan trade deal that were announced on September 4.
Q2: What happens next, and who are the candidates to replace Ishiba?
A2: The LDP is expected to release details about the leadership election this week, with a vote most likely to take place in early October. Outgoing LDP Secretary-General Moriyama emphasized the need to reflect the broader voices of party members in selecting its new leader. As a result, the voting is likely to involve 295 sitting LDP lawmakers in the National Diet and 295 votes allocated to rank-and-file party members nationwide, rather than a faster yet limited process of 295 sitting lawmakers and 141 representatives across Japan’s 47 prefectures. The latter was last used in 2020 when former prime minister Shinzo Abe resigned.
Sanae Takaichi, a former economic security minister known for her conservative views as a protégé of former prime minister Abe, currently tops public opinion polls alongside Shinjiro Koizumi, who has been leading the government’s response to the rice crisis since becoming minister of agriculture, forestry, and fisheries in May 2025 and is backed by Suga. Toshimitsu Motegi, a veteran lawmaker with extensive experience, including a stint as foreign minister, was the first to declare his intention to enter the race. Chief Cabinet Secretary Yoshimasa Hayashi, who previously served as foreign minister under Fumio Kishida, is also said to be weighing a run. Another potential contender is Takayuki Kobayashi, a younger conservative lawmaker who has also held the post of economic security minister. Candidates must secure at least 20 endorsements from fellow LDP lawmakers to qualify for the ballot, a requirement that could shape the final field. All of these potential candidates ran last year, when Takaichi lost to Ishiba in a runoff.
Q3: What are the implications for Japanese politics and foreign policy?
A3: The next LDP president will face the challenge of bringing together an increasingly divided party and recapturing the support and trust of a Japanese public that is frustrated with economic conditions and political scandals. Given recent electoral losses, there are currently debates within the LDP about whether it should shift right to recapture voters that have flocked to populist parties like Sanseito and the Democratic Party for the People, or whether it should instead move to the center to appeal to urban voters who also feel excluded from the LDP’s current vision. These decisions will reveal party instincts about whether to seek new coalition partners from within the political opposition, and they will also have important consequences for policies related to inflation relief, tax cuts, immigration, and other issues that the opposition will try to influence. Since the LDP does not currently control the National Diet, it is not guaranteed that the next LDP president will become prime minister, but he or she will be a very likely candidate considering divisions among the opposition parties.
In terms of U.S.-Japan relations, Japan’s next leader will inherit a complex, ongoing set of negotiations with its key ally on both the economic and security fronts. The trade agreement implementation plan agreed upon by the United States and Japan last week provides a roadmap forward, but the United States has explicitly retained the right to increase tariffs if Japan fails to make meaningful progress. Tariffs will likely remain a source of tension in the months to come, and the Trump administration has already indicated that it wants Japan to do more in terms of defense spending and alliance burden sharing, which will present difficulties given Japan’s current domestic economic and political constraints. Strong leadership will be necessary for Japan to nimbly respond to rapidly evolving U.S. foreign policy and find productive ways to cooperate moving forward in the face of intensifying security threats from China, North Korea, and Russia.
However, the increasing fluidity and instability of domestic politics present potential challenges for Japan’s ability to exercise effective, stable leadership at home and abroad. The LDP-Komeito coalition’s weakened position means that they are now reliant on deals with opposition parties to pass legislation and vulnerable to votes of no confidence. The political opposition is similarly divided and lacks consensus about future directions for Japanese policy. In short, Japan could be mired in another period of political instability consistent with a historical pattern where a succession of short-lived leaders follow long tenures under strong prime ministers. For example, after Junichiro Koizumi’s six-year prime ministership from 2001 to 2006, Japan had six prime ministers in six years. Since Shinzo Abe’s eight-year term ended in 2020, Suga, Kishida, and now Ishiba have stepped down within a span of five years. Sound leadership is necessary to address the serious challenges that Japan faces in getting its economy in order, bridging emerging social divides, and defining Japan’s international role in response to the rise of authoritarianism and a less predictable United States. The stakes are high, and the LDP leadership race in the coming weeks will help determine whether Japan is up to the challenge.
Kristi Govella is senior adviser and Japan Chair at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Nicholas Szechenyi is vice president of the geopolitics and foreign policy department and senior fellow with the Japan Chair at CSIS. Yuko Nakano is a fellow with the Japan Chair and associate director of the U.S.-Japan Strategic Leadership Program at CSIS.
AloJapan.com