James Liu has always considered himself a patriot.

With a lump in his throat, he watched a military parade on National Day, China’s birthday, that showed a once backward nation that had become strong and powerful. He got goose bumps watching “Wolf Warrior 2,” a “Rambo”-like Chinese blockbuster featuring a superhero veteran who single-handedly rescues his countrymen trapped abroad.

When China came under attack online, Mr. Liu was one of the legions of Chinese students studying abroad who posted in its defense. He condemned the pro-democracy protests in Hong Kong, which he saw as an effort to split a uniting China. After President Trump called the coronavirus the “Chinese virus,” Mr. Liu turned to Twitter to correct those who used the term.

“I was a real little pink,” he said, using a somewhat derogatory term for the young, Communist-red Chinese nationalists who use the internet as a patriotic battleground to fight those who disparage China.

Then Mr. Liu, 21, discovered that the country he had long defended didn’t want him back.

The fresh graduate from a Midwestern university had become one of an untold number of Chinese people stranded abroad by the coronavirus pandemic. Flights had vanished. Tickets home were outrageously expensive. The Chinese government, fearful that people like him would bring the virus with them, restricted international flights and told its expatriates to stay put.

When overseas students went online to question why they couldn’t fly home, people in China told them to stay away. The students, they said, were spoiled brats who could jeopardize China’s success in containing the epidemic.

Mr. Liu and many other countless Chinese people stranded overseas are, for the first time, running afoul of one of their country’s bedrock political principles: National interests come before an individual’s needs. That may sound reasonable, even logical, but it differs sharply from the sentiment in places, like the United States and elsewhere, where the rights of the minority are supposed to be protected.

In this case, the stranded students and workers have become a minority group that is expected to sacrifice for the benefit of the majority. That puts them among the ranks of government critics and the Hong Kong pro-democracy protesters — people they have long battled online.

Some of the little pinks are rethinking their relationship with the country — which, in the Chinese context, is the nation, the government and the Communist Party all in one.

“My feelings are increasingly complicated,” Mr. Liu wrote on the social media platform Weibo in mid-May. “The country I loved doesn’t want me back.” Reading the many critical social media posts against overseas students like him, he felt as if he had been “beaten up badly,” he told me in a phone interview.

Their views could someday help shape China’s relationship with the world. Some will grow up to be leaders in business, academia or other institutions. They will most likely remain patriots, but they will have a more nuanced view of their country. And they may not be so quick to believe what they hear from their government.

“Can you imagine what it was like when one day someone told you what you believed firmly wasn’t actually true?” Mr. Liu said.

Daisy Leng, a third-year exchange student at Troy University in Alabama who finished her program but struggled to get a plane ticket home, wrote on Weibo that she truly loved her country and had fought against people who dared to smear China. But after four flight cancellations because of government restrictions, she was frustrated.

“My heart had turned cold,” she wrote, adding a broken-heart emoticon.

It isn’t clear how many are in a similar predicament. Mr. Liu and Ms. Leng are among more than 1.4 million Chinese students who were living in foreign countries as of April 2, with nearly one-third in the United States.

Many didn’t rush home in February or March because the coronavirus situation looked worse at home. Others wanted to finish the semester rather than return home and take classes online with a punishing time difference. Some listened to the Chinese government, which told them to stay safe but stay put.

Then the pandemic hit the rest of world. China’s aviation regulator began limiting how often foreign airlines could fly to the country. Chinese carriers flew abroad but with limited capacity. At the same time, less prosperous countries like India were organizing pickups for their stranded citizens.

Many Chinese students went to the official Weibo account of China’s aviation regulator to plead and to protest canceled flights and high ticket prices. For them, China was like a beautiful but unattainable dream.

“This is a time of prosperity, like you wished for,” said many, quoting a state media catchphrase urging Chinese people to feel grateful for living in a successful country.

Many of the students belong to what might be the most nationalistic generation since China opened up to the world more than four decades ago. They grew up amid tightening censorship and increasingly strident propaganda. In school, they were taught incessantly that China was humiliated for a century by Western countries.

Exposure to foreign cultures and languages has not made many of them more receptive to foreign ideas. Social media, especially WeChat, is so powerful that they mostly live in a China bubble in foreign lands.

And the Communist Party has mastered the art of stirring their patriotism. One of its success stories is “Wolf Warrior 2,” the 2017 action movie that became China’s biggest hit and stirred people like Mr. Liu.

Near the end of the movie, after a long shot of the Chinese veteran in an African nation waving his country’s flag, a sentence is typed out word by word on the back of a red Chinese passport: “Citizens of the People’s Republic of China, don’t give up when you encounter dangers abroad! Please remember, behind you stands a strong motherland!”

For many of these students, these words sound empty now. “In the real world, there’s no wolf warrior coming to my rescue,” a Chinese student in Japan posted on Weibo.

In early April, Mr. Liu bought a Delta Air Lines ticket for about $900 for a June flight to Shanghai. Then Delta’s flight was canceled when the Chinese authorities restricted U.S. carriers.

Prices rose. One of his friends paid $10,000 for a seat in coach. Mr. Liu expects his first job will pay him a little over $1,000 a month. Studying in the United States had cost his parents a lot of money.

In the following weeks, Mr. Liu didn’t sleep well, getting by with five or six hours a night. He joined chat groups that exchanged information about flights. He found one ticket for $4,000 — a reasonable price by then — that would take him through New York, Mexico City and Tokyo. His mother vetoed the plan. Too many transfers would increase his exposure to the virus.

Finally, he booked a flight through Los Angeles and Seoul, South Korea, to the Chinese city of Xiamen, 370 miles from his hometown. Cost: $2,500.

“I felt much better now that I got the ticket,” he said. “I almost started questioning the meaning of life.”

While the students were outspoken in their anonymous social media comments, they were more reserved in interviews. Mr. Liu, for example, focused his frustration on China’s aviation regulator, which recently backed down after U.S. officials challenged its limits on foreign airlines. Ms. Leng, of Troy University, said she understood the regulator’s motivations.

But some admitted to what might be a new feeling: fear. The student from Japan who invoked “Wolf Warrior 2” said she feared retribution by the Chinese government if she spoke to me.

Then she invited me into a WeChat group of nearly 500 Chinese students exchanging information about flights, visas, schools and frustrations. They told one another not to give news interviews, not even to the Chinese media, for fear of government punishment.

When they sometimes couldn’t help curse the government or the policy, someone would quickly warn that they had better shut up or risk losing their WeChat accounts or even being invited for a chat once they’re back in China.

One student, after being warned, posted an emoticon of the 12 core socialist values that every Chinese citizen is supposed to live by, posting it five times in a row, as if pledging his loyalty to the surveillance state.

“I grew up under the red flag and received the red education,” Mr. Liu said to me. “But what can I say now?”