Japan Faces Big Problems. Its Next Leader Offers Few Bold Solutions.

TOKYO — With the world’s oldest population, rapidly declining births, gargantuan public debt and increasingly damaging natural disasters fueled by climate change, Japan faces deep-rooted challenges that the longstanding governing party has failed to tackle.

Yet in choosing a new prime minister on Wednesday, the Liberal Democratic Party elected the candidate least likely to offer bold solutions.

The party’s elite power brokers chose Fumio Kishida, 64, a stalwart moderate, in a runoff election for the leadership, seeming to disregard the public’s preference for a maverick challenger. In doing so, they anointed a politician with little to distinguish him from the unpopular departing leader, Yoshihide Suga, or his predecessor, Shinzo Abe, Japan’s longest-serving prime minister.

Elders in the party, which has had a near monopoly on power in the decades since World War II, made their choice confident that, with a weak political opposition and low voter turnout, they would face little chance of losing a general election later this year. So, largely insulated from voter pressure, they opted for a predictable former foreign minister who has learned to control any impulse to stray from the mainstream party platform.

“In a sense, you are ignoring the voice of the rank and file in order to get somebody the party bosses are more comfortable with,” said Jeff Kingston, the director of Asian studies at Temple University in Tokyo.

But choosing a leader who lacks popular support carries the risk of a backlash that leaves the party weaker after the election and makes Mr. Kishida’s job harder as the country slowly emerges from six months of pandemic restrictions that have battered the economy.

Mr. Kishida will need to win the public’s trust to show that he is not just a party insider, said Kristi Govella, the deputy director of the Asia Program at the German Marshall Fund of the United States.

“If challenges start to arise,” she said, “we could see his approval ratings decrease very quickly because he is starting from a point of relatively modest support.”

Mr. Kishida was one of four candidates who vied for the leadership post in an unusually close race that went to a runoff between him and Taro Kono, an outspoken nonconformist whose common touch has made him popular with the public and with rank-and-file party members. Mr. Kishida prevailed in the second round of voting, in which ballots cast by members of Parliament held greater weight.

He will become prime minister when Parliament holds a special session next week, and will then lead the party into the general election, which must be held by November.

In his victory speech on Wednesday, Mr. Kishida acknowledged the challenges he faces. “We have mountains of important issues that lie ahead in Japan’s future,” he said.

They loom both at home and abroad. Mr. Kishida faces mounting tensions in the region as China has grown increasingly aggressive and North Korea has started testing ballistic missiles again. Taiwan is seeking membership in a multilateral trade pact that Japan helped negotiate, and Mr. Kishida may have to help finesse a decision on how to accept the self-governed island into the group without angering China.

As a former foreign minister, Mr. Kishida may have an easier time managing his international portfolio. Most analysts expect that he will maintain a strong relationship with the United States and continue to build on alliances with Australia and India to create a bulwark against China.

But on the domestic front, he is mostly offering a continuation of Mr. Abe’s economic policies, which have failed to cure the country’s stagnation. Income inequality is rising as fewer workers benefit from Japan’s vaunted system of lifetime employment — a reality reflected in Mr. Kishida’s campaign promise of a “new capitalism” that encourages companies to share more profits with middle-class workers.

“Japan’s accumulated debt is growing, and the gap between rich and poor is growing,” said Tsuneo Watanabe, a senior fellow at the Sasakawa Peace Foundation in Tokyo. “I don’t think even a genius can tackle this.”

On the pandemic, Mr. Kishida may initially escape some of the pressures that felled Mr. Suga, as the vaccine rollout has gathered momentum and close to 60 percent of the public is now inoculated. But Mr. Kishida has offered few concrete policies to address other issues like aging, population decline or climate change.

In a magazine questionnaire, he said that he needed “scientific verification” that human activities were causing global warming, saying, “I think that’s the case to some extent.”

Given the enduring power of the right flank of the Liberal Democratic Party, despite its minority standing in the party, Mr. Kishida closed what daylight he had with these power brokers during the campaign.

He had previously gained a reputation as being more dovish than the influential right wing led by Mr. Abe, but during the leadership race, he expressed a hawkish stance toward China. As a parliamentary representative from Hiroshima, Mr. Kishida has opposed nuclear weapons, but he has made clear his support for restarting Japan’s nuclear power plants, which have been idled since the triple meltdown in Fukushima 10 years ago.

And he toned down his support for overhauling a law requiring married couples to share a surname for legal purposes and declared that he would not endorse same-sex marriage, going against public sentiment but hewing to the views of the party’s conservative elite.

“I think Kishida knows how he won, and it was not by appealing to the general public, it was not by running as a liberal, but courting support to his right,” said Tobias Harris, a senior fellow at the Center for American Progress in Washington. “So what that’s going to mean for the composition of his cabinet and his priorities, and what his party’s platform ends up looking like, means he could end up being pulled in a few different directions.”

In many respects, Wednesday’s election represented a referendum on the lasting clout of Mr. Abe, who resigned last fall because of ill health. He had led the party for eight consecutive years, a remarkable stint given Japan’s history of revolving-door prime ministers. When he stepped down, the party chose Mr. Suga, who had served as Mr. Abe’s chief cabinet secretary, to extend his boss’s legacy.

But over the past year, the public grew increasingly disillusioned with Mr. Suga, who lacked charisma and failed to connect with average voters. Although Mr. Abe backed Sanae Takaichi — a hard-line conservative who was seeking to become Japan’s first female prime minister — to revitalize his base in the party’s far right, analysts and other lawmakers said he helped steer support to Mr. Kishida in the runoff.

As a result, Mr. Kishida may end up beholden to his predecessor.

“Kishida cannot go against what Abe wants,” said Shigeru Ishiba, a former defense minister who challenged Mr. Abe for the party leadership twice and withdrew from running in the leadership election this month to support Mr. Kono.

“I am not sure I would use the word ‘puppet,’ but maybe he is a puppet?” Mr. Ishiba added. “What is clear is he depends on Abe’s influence.”

During the campaign for the party leadership, Mr. Kishida appeared to acknowledge some dissatisfaction with the Abe era with his talk of a “new capitalism.” In doing so, he followed a familiar template within the Liberal Democratic Party, which has been adept at adopting policies first introduced by the opposition in order to keep voters assuaged.

“That’s one of the reasons why they have maintained such longevity as a party,” said Saori N. Katada, a professor of international relations at the University of Southern California. “Kishida is definitely taking that card and running with it.”

Makiko Inoue, Hikari Hida and Hisako Ueno contributed reporting.