The National Zoo’s three giant pandas — Mei Xiang, Tian Tian and their cub Xiao Qi Ji — are set to return to China in early December with no public signs that the 50-year-old exchange agreement struck by President Richard Nixon will continue.

Officials at the National Zoo in Washington have remained tight-lipped about the prospects of renewing or extending the agreement, and repeated attempts to gain comment on the state of the negotiations did not receive a response. However, the public stance of the zoo has been decidedly pessimistic — treating these remaining months as the end of an era. The zoo just finished a weeklong celebration called Panda Palooza: A Giant Farewell.

The potential end of the National Zoo’s panda era comes amid what veteran China-watchers say is a larger trend. With diplomatic tensions running high between Beijing and a number of Western governments, China appears to be gradually pulling back its pandas from Western zoos as their agreements expire.

Dennis Wilder, a senior fellow at Georgetown University’s Initiative for U.S.- China Dialogue on Global Issues, called the trend “punitive panda diplomacy,” noting that two other American zoos have lost their pandas in recent years, while zoos in Scotland and Australia are facing similar departures with no signs of their loan agreements being renewed.

Beijing lends out 65 pandas to 19 countries through “cooperative research programs” with a stated mission to better protect the vulnerable species. The pandas return to China when they reach old age and any cubs born are sent to China around age 3 or 4.

The San Diego Zoo returned its pandas in 2019, and the last bear at the Memphis Zoo went home earlier this year. The departure of the National Zoo’s bears would mean that the only giant pandas left in America are at the Atlanta Zoo — and that loan agreement expires late next year.

Wilder said the Chinese possibly could be “trying to send a signal.”

He cited a litany of Chinese-American flashpoints: sanctions imposed by the U.S. government on prominent Chinese citizens and officials; restrictions on the import of Chinese semiconductors; accusations that Chinese-made fentanyl is flooding American cities; suspicion over Chinese ownership of the social media platform TikTok; and the uproar early this year over the Chinese balloon floating over America.

Beijing, Wilder said, is convinced that “NATO and the United States are lining up against China.”

The panda-related tension has even spilled into the hallways of the U.S. Senate. Last week, Pennsylvania Democrat John Fetterman complained about China buying up American farmland and added, “I mean, they’re taking back our pandas. You know, we should take back all their farmland.”

That animosity has been at least partially shared by the public in China, where anti-American sentiments are on the rise. Those sentiments developed into a perfect panda storm earlier this year when Le Le, a male panda on loan to the zoo in Memphis, died suddenly in February at the age of 24. Pandas generally live 15 to 20 years in the wild, while those in human care often live to be around 30.

Le Le’s unexpected death prompted an explosion on Chinese social media platforms like Weibo, with widespread allegations that the Memphis Zoo had mistreated the bear and its female companion, Ya Ya. The campaign gained intensity when photos circulated on the internet of Ya Ya looking dirty and gaunt (by panda standards) with patchy fur.

An online petition on Change.org demanded Ya Ya be returned immediately, alleging malnourishment and deprivation of proper medical care. Slogans such as “the panda’s life matters” surfaced in China’s social media along with emotional memes pleading with authorities to rescue the bear. One particular meme depicts a miserable-looking Ya Ya gazing at a plane flying overhead with the caption: “Mama, I have worked away from home for 20 years. Have I earned enough for a plane ticket to return home?”

The heat grew so intense that the Memphis Zoo released a statement responding to what it called “misinformation” about its pandas and stating that Ya Ya has “a chronic skin and fur condition” that “makes her hair look thin and patchy” and that Le Le died of natural causes.

Even an official Chinese scientific delegation that visited Memphis and announced that Le Le was not mistreated and died of a heart condition failed to quell the outrage. Ya Ya was returned to China on schedule in April when the loan agreement expired and received a celebrity’s welcome at Shanghai’s airport.

The Chinese government, which gifted the first pair of pandas — Hsing Hsing and Ling Ling — to the U.S., now leases the pandas out for a typical 10year renewable term. The annual fee ranges from $1 million to $2 million per pair, plus mandatory costs to build and maintain facilities to house the animals. Any cub born to the pandas belongs to the Chinese government but can be leased for an additional fee until it reaches mating age.