Sport, they say, is a bridge between nations. If so, then China and the United States should be worried, after a "goodwill" exhibition game in Beijing between an American college basketball team and a local club descended into an on-court mêlée that overshadowed the diplomatically sensitive visit by the Vice-President, Joe Biden.
"Unfortunate", was the response of the US and Chinese foreign ministry spokesmen yesterday to the brawl on Thursday night, which came close to the end of the contest between Georgetown University in Washington DC – Bill Clinton's old Alma Mater – and the Bayi Military Rockets, a professional team drawn from the ranks of the People's Liberation Army.
"We look to these games to promote good sportsmanship," a US official told The Washington Post. "And to strengthen people-to-people contact with China." But half a dozen separate fist fights between opposing Chinese and American players were probably not what he had in mind.
For the Americans, there was no doubt who was to blame. "The situations we were put in went beyond losing your cool. In the end it was a matter of 'I need to protect myself,'" John Thompson, Georgetown's coach, said.
As soon as the fighting subsided, Thompson called his players off the court. "We were very much outnumbered. My only thought was to get our fans, our players, our family, out of this building as soon as possible."
The tour of the "Hoyas", as Georgetown is known, will continue, however. As will the visit of Mr Biden, who providentially attended the American team's game on the previous evening, which passed without incident.
Yesterday it was business as usual for the Vice-President, who assured his hosts they had "nothing to worry about" over the safety of their vast holdings of Treasury debt and delivered a resounding endorsement of the strength of the US economy, despite its massive debts and the growing risk of a double-dip recession.
China's Prime Minister, Wen Jiabao, expressed confidence that the US would soon return to robust growth, but he warned that Washington had to "keep its word and its obligations with regard to its government debt." And, in basketball at least, relations between the world's two biggest economies have just been downgraded even more than the US credit rating.