BEIJING — China is pushing a new theory about the origins of the coronavirus: It is an American disease that might have been introduced by members of the United States Army who visited Wuhan in October.
There is not a shred of evidence to support that, but the notion received an official endorsement from China’s Ministry of Foreign Affairs, whose spokesman accused American officials of not coming clean about what they know about the disease.
The intentional spreading of an unfounded conspiracy theory — which recirculated on China’s tightly controlled internet on Friday — punctuated a downward spiral in relations between the two countries that has been fueled by the basest instincts of officials on both sides.
The insinuation came in a series of posts on Twitter by Zhao Lijian, a ministry spokesman who has made good use of the platform, which is blocked in China, to push a newly aggressive, and hawkish, diplomatic strategy. It is most likely intended to deflect attention from China’s own missteps in the early weeks of the epidemic by sowing confusion or, at least, uncertainty at home and abroad.
Mr. Zhao’s posts appeared to be a retort to similarly unsubstantiated theories about the origins of the outbreak that have spread in the United States. Senior officials there have called the epidemic the “Wuhan virus,” and at least one senator hinted darkly that the epidemic began with the leak of a Chinese biological weapon.
“The conspiracy theories are a new, low front in what they clearly perceive as a global competition over the narrative of this crisis,” said Julian B. Gewirtz, a scholar at the Weatherhead Center for International Affairs at Harvard.
“There are a few Chinese officials who appear to have gone to the Donald J. Trump School of Diplomacy,” added Mr. Gewirtz, who recently published a paper on China’s handling of the AIDS epidemic, after a similar disinformation campaign. “This small cadre of high-volume Chinese officials don’t seem to realize that peddling conspiracy theories is totally self-defeating for China, at a moment when it wants to be seen as a positive contributor around the world.”
The circulation of disinformation is not a new tactic for the Communist Party state. The United States, in particular, is often a foil of Chinese propaganda efforts. Last year, Beijing explicitly accused the American government of supporting public protests in Hong Kong in an effort to weaken the party’s rule.
The old tactic has been amplified by more combative public diplomacy and a new embrace of a social media platform that is blocked in China to spread a message abroad.
Victor Shih, an associate professor at the University of California at San Diego who studies Chinese politics, said that while the campaign was very likely an attempt to distract and deflect blame, a more worrisome possibility was that some officials fabricated the idea and persuaded top leaders to believe it.
“If the leadership really believes in the culpability of the U.S. government,” he warned, “it may behave in a way that dramatically worsens the bilateral relationship.”