Peter Martin | (TNS) Bloomberg News WASHINGTON — U.S. spies believe China’s leaders see little or no upside to the looming electoral showdown between President Joe Biden and his predecessor Donald Trump. Ahead of next week’s first debate of the presidential campaign, U.S. intelligence agencies assess that China has no clear preference between the two candidates, according to American officials, who asked not to be identified discussing nonpublic assessments. The conclusion suggests that officials in Beijing, like their counterparts in Washington, believe that ties between the world’s two largest economies will continue on their long-term downward trajectory despite a recent increase in high-level meetings billed as efforts to manage differences.