TOKYO — Compared with the United States and Europe, countries in East Asia have been held up as success stories in the battle against the coronavirus pandemic.

But in Japan, South Korea and Hong Kong, governments are reimposing restrictions this week, as public complacency, policy blunders and colder weather fuel a new surge in virus cases.

Japan is scaling back a contentious subsidy program designed to encourage domestic tourism and dining out, after it became clear the enticements were helping to fuel a third wave that has resulted in record new infections.

In Seoul, officials ordered bars and nightclubs to close and limited dine-in service at cafes and restaurants this week, after an earlier easing of restrictions allowed the virus to roar back.

Hong Kong also closed bars and nightclubs, days after officials postponed the launch of a travel bubble with Singapore — a highly anticipated experiment that was set to herald a reopening of quarantine-free travel in Asia — after the virus found gaps in the territory’s defenses to stage a comeback.

The numbers of new infections here are a fraction of those in West, with Japan recently reporting more than 2,000 new cases a day, South Korea more than 300 a day, and Hong Kong recording 73 new confirmed cases on Monday — compared with more than 150,000 a day in the United States.

Yet the infection rates are still high enough to ring alarm bells, especially given the high proportion of elderly people in places like Japan, as winter approaches and doors and windows close against the chill.

Pandemic fatigue is a key ingredient, experts say. After many months of restrictions and with cases seemingly under control for a while, people have become tired of the rules, bored with staying at home and complacent about the risks.

On Tokyo’s streets this past week, everybody has been wearing a mask. But bars and restaurants have been packed with people who have cast their face coverings aside.

“Our control measures rely on voluntary behavior change,” said Hitoshi Oshitani, a professor at Tohoku University’s Graduate School of Medicine who is a member of the government’s coronavirus advisory team. “And it’s getting more difficult to persuade people to change behavior. Even though the number of cases is much, much higher than in March or April, people are quite relaxed.”

Kang Do-tae, South Korea’s vice health minister, warned Tuesday of a “triple bind” of asymptomatic patients, transmission among young people, and colder weather in which the virus thrives because of increased indoor activity.

“The unforeseen development of the third wave forewarns an even harsher and harder winter,” Kang told government officials at a meeting to discuss the coronavirus response.

As the peak of flu season approaches and hospital beds fill up, that complacency is increasingly dangerous, experts say.

But there have also been policy blunders, U-turns and misfires that have given the virus the opportunity to spread.

To rescue its economy from a record slump, the Japanese government launched the Go to Travel and the Go to Eat subsidy programs in July and October, respectively, offering to repay consumers up to half the costs of flights, hotels, meals and other expenses. The aid brought welcome relief to industries floored by the pandemic, but it also helped the virus to penetrate new corners of this island nation.

On Monday, the governors of the northern prefecture of Hokkaido and the western prefecture of Osaka announced they were withdrawing their regional capital cities from the subsidy program, a decision the central government reluctantly endorsed the next day.

Tokyo Governor Yuriko Koike also raised concerns Tuesday.

“It is clear that the movement of people is having an impact on this increase in cases,” she said at a news conference. “And we are seeing these situations where in times of eating out, the virus does spread. This is then brought home into the household, where perhaps there are elderly members of the family who have lower immunity.”

Opposition politicians slammed the government, saying it was acting too late. Yoshimasa Suenobu, a veteran journalist and a professor of media studies at Tokai University, said it was as though the government was driving a car “without thinking about how to brake.”

“A car won’t drive well unless both the accelerator and the brake perform equally well,” he said on Nippon Broadcasting System.

In South Korea, which won praise for effectively tamping down the first major epidemic outside China, officials have continued to fight small but persistent outbreaks.

Believing it had a second wave under control, the government eased social distancing rules last month. Over the past two weeks, however, more than 60 infection clusters emerged across the country, including at schools, military bases and churches.

“Infections from the first and second waves left lingering transmission risks across the South Korean society, which caught fire as social distancing rules were lifted without proper preparations,” said Kim Yoon, a professor at Seoul National University’s College of Medicine, warning the outbreaks could overwhelm South Korea’s contact-tracing regime.

“Unlike previous outbreaks which stemmed from few big clusters, the third wave consists of dozens of small clusters that are harder for contact tracers to track,” he added.

In Hong Kong, a cluster of infections originating from dance clubs has shattered a weeks-long streak of low to zero local cases. That cluster has emerged as one of the biggest Hong Kong has seen, with more than 130 confirmed cases.

The city’s government has moved belatedly to close loopholes that had given the virus a path back, including lax hotel quarantine arrangements for returning residents, who were forced to quarantine for 14 days but could still have visitors.

But the financial hub is also battling a similar wave of fatigue and complacency that Japan has experienced.

“Seeing videos and photos of the dancing clusters that have gone viral, we can see people totally not respecting the regulations during a pandemic,” Hong Kong Chief Executive Carrie Lam said Tuesday, pointing out that people were engaged in close-contact activities without masks on.

“It seems like this new wave of infection will be quite severe.”

Akiko Kashwagi in Tokyo, Min Joo Kim in Seoul, and Theodora Yu and Shibani Mahtani in Hong Kong contributed to this report.