When Ya Ya, a giant panda from China, landed in the United States in 2003, several hundred spectators at the Memphis International Airport broke into cheers to welcome the fluffy goodwill ambassador from Beijing. The moment encapsulated a high-point in US-China relations, coming two years after China joined the World Trade Organization with American support, and as the two countries deepened engagement in areas ranging from the economy to counter-terrorism. Two decades later, as Ya Ya bid farewell to the US and boarded a plane heading back to China on Wednesday, she has become a symbol of deteriorating relations between the world’s two superpowers, which have fallen to their lowest point in half a century. She landed in Shanghai Thursday after a 16-hour flight, carried home by a special FedEx “panda express” plane, Chinese state media reported. For nearly three months, heated discussions in China about the treatment of Ya Ya by the Memphis Zoo have served to highlight just how antagonistic the US-China relationship has become. Unlike the chubby, fluffy image of her younger self, 22-year-old Ya Ya has appeared skinny in recent photos, with her black and white coat missing clumps of fur. Many in China have been shocked and saddened by her condition. Some believed she had not been given proper care and attention – an accusation first levied by animal advocates in 2021 but denied repeatedly by the Memphis Zoo. Ya Ya and her male companion, Le Le, were due to return to China this year after the end of a 20-year loan. But Le Le died suddenly of heart disease in early February, further fueling suspicions of mistreatment. As part of China’s “panda diplomacy,” these bears are meant to serve as an envoy of friendship between China and their host country. But for Chinese nationalists, Ya Ya has become a glaring symbol of what they see as America’s bullying and suppression of China. “Treating our national treasure with such an attitude is an outright provocation of China,” said a comment on Weibo, China’s heavily censored Twitter-like platform. Meanwhile, videos of two playful, energetic pandas at the Moscow Zoo went viral on Chinese social media, drawing effusive praise for Russia for its care of the Chinese bears. The apparent contrast between the pandas in the US and Russia was seized on by Chinese state media, which has taken on a pro-Russian stance since Moscow’s invasion of Ukraine and regularly fanned anti-US sentiment. Determined to rescue Ya Ya from her perceived ordeal, Chinese internet users rallied to bring the panda home as soon as possible. Some joined an online petition calling for her immediate return, others followed her every move on the zoo’s panda cams livestreams. Chinese people living in the US also took turns to visit her and shared updates on her condition – some flying in from as far as Los Angeles. Throughout the past weeks, Ya Ya regularly appeared as a top trending topic on Weibo, each time attracting hundreds of millions of views. Photos of her were placed on advertising billboards from New York to Shanghai, along with the message:”Ya Ya, we’re waiting for you to come home.” Like her arrival in the US, her return to China is laden with symbolism – this time not of growing friendship, but of mounting animosity and distrust. Diplomatic tool For eight decades, pandas have served as a something of a barometer of China’s international relations. Beijing has used the bears as a political tool since 1941, when it gifted a pair of cubs to Washington as gratitude for American assistance in fighting the Japanese invasion. After the Communist Party took power, panda exchanges were initially limited to China’s socialist allies – North Korea and the Soviet Union. But as Beijing began to reconnect with the world, the bears became goodwill ambassadors to the West as well. During US President Richard Nixon’s historic ice-breaking trip to China in 1972, his wife visited the Beijing zoo and was reportedly charmed by its giant pandas. Weeks later, a pair of pandas arrived at the National Zoo in Washington DC. “It was the first one that made a really big splash,” said E. Elena Songster, a historian at the Saint Mary’s College of California and author of the book Panda Nation. “You have this transformation from these early gifts that were to express friendship or gratitude to this dramatic diplomatic gesture, that was reflecting a shift in the relation from enemy state to one of friendship,” she said. In 1984, China stopped giving away its pandas for free and switched to a policy of high-priced loans. At first, the bears were rented out to foreign zoos for short-term exhibitions. It was later replaced by long-term “research” loans, which typically last 10 years and cost $1 million annually – money that Beijing said will go to conservation of the species. China currently loans its pandas to about 20 countries around the world. Over the past decade, Chinese leader Xi Jinping has greatly expanded “panda diplomacy” in Europe, approving new loans to countries from Germany, the Netherlands and Denmark to Finland. Last year, China sent a pair of pandas to Qatar, in the first loan to a Middle Eastern country. In contrast, China has not granted any panda loans to the US for two decades, since Ya Ya and Le Le arrived in Memphis, said Masaki Ienaga, an associate professor at Tokyo Woman’s Christian University. Songster said China does seem to recognize the pandas are valuable for serving its needs. “As its needs change, the use of the pandas shifts, but it’s always serving the needs of the government at the time,” she said. Allegations of mistreatment When Ya Ya and Le Le arrived at Memphis in 2003, it was a huge deal for the city. The bears had a red-carpet welcome and instantly became one of the city’s most popular attractions. In 2013, the zoo renewed the panda loan for another decade. Since at least 2019, however, Memphis Zoo has faced concerns from visitors and panda fans that Ya Ya looked a little thin and discolored. It has repeatedly dismissed speculations that the bear was sick or malnourished. Instead, zoo officials and vets maintained Ya Ya was simply small framed but healthy, and attributed her fur loss to hormones. A page on the zoo’s website dedicated to the pandas details the care Ya Ya received, including how often she was given bamboo and medical checkups. Animal advocates disagreed and accused the zoo of mistreating the bears. Panda Voices, an advocacy group for Ya Ya and Le Le founded by a group of overseas Chinese students, and California-based animal rights nonprofit In Defense of Animals launched an online campaign to bring the pandas back to China. In December, the Memphis Zoo said it would send Ya Ya and Le Le back home when their lease expires in 2023 (It denied the decision was related to allegations of their mistreatment). Two months later, it announced Le Le had died unexpectedly. Panda Voices and In Defense of Animals claimed Le Le had shown signs of ailing health on the panda cam days before his death and accused the zoo of neglect. Zoo officials refuted the allegations, saying the panda was in good health up until his death. The Memphis Zoo did not respond to CNN’s repeated requests for comment. The fallout Le Le’s sudden death, along with long-running accusations of mistreatment against the Memphis Zoo, caused an uproar in China. The Chinese Association of Zoological Gardens, the organization responsible for arranging China’s panda loans, dispatched a team of experts to Memphis to investigate Le Le’s death. An autopsy conducted by Chinese and American scientists found he died of heart disease, according to the association. The Chinese experts also examined Ya Ya and reviewed her medical reports. The bear was suffering hair loss caused by a skin disease, but otherwise had a good appetite, normal stools and a stable weight, the association said. Xie Zhong, the deputy head of the association, told Chinese state media Ya Ya’s skin condition was related to her family genes. It had worsened with age and seasonal hormone changes and was difficult to treat, she added. But many in China remained unconvinced and turned their wrath at the Chinese Association of Zoological Gardens. Some accused it of colluding with the zoo and called for the association to be investigated, punished or even disbanded outright. Meanwhile, backlash against the Memphis Zoo continued, with many calling for the zoo to be blacklisted from future panda loans. Others demanded all pandas in the US to be sent home. Some even called for an end to “panda diplomacy” all together, comparing the overseas pandas to the ancient Chinese princesses married off by the emperor as a peace offering to the country’s enemies. China used its pandas as a diplomatic tool when it was weak; now, as a global superpower, it no longer needs to send its national treasures to other countries, they argued. As Ya Ya makes her way back to China, Chinese officials also appeared to attempt to tamp down the domestic public anger that had become so ubiquitous in recent months on the country’s heavily censored internet. A spokesperson for the Chinese Foreign Ministry said Wednesday Ya Ya and Le Le had been “well taken care of” by the Memphis Zoo and “loved by the American people.” “China is willing to continue to work with other partners, including the US, to contribute to the conservation of endangered species,” said spokesperson Mao Ning. At the Beijing Zoo, where Ya Ya was born and will spend the rest of her life, visitors packed its panda house in anticipation of the bear’s return. On a recent Tuesday, multiple visitors at the zoo told CNN they were glad Ya Ya is coming home. “I’ve heard that the US is treating the panda poorly,” said an 11-year-old child. His mother added: “The panda returning to the motherland is something the whole nation has been looking forward to. We feel happy and excited.” An elderly man with a baby stroller said China should be more selective in giving pandas away an “exchange of friendship.” “Why would we want to send them to unfriendly countries?” he asked. “(Pandas in Russia) are very happy. Why? Russians and Chinese are friends. At least Russia is not sanctioning China.” An earlier version of this story misgendered Xie Zhong.