Cultural ties between the US and China are at a low point after several years of decline, according to Guardian analysis of official figures. The Covid-19 pandemic and travel restrictions, coupled with the continuing trade war between the two countries, is diluting cultural exchanges, with visitor numbers, students and even the world of literature all affected. During the late 2000s and early 2010s there was an increase in cultural exchange between the US and China. Since then, tensions between the two countries – which rose under Donald Trump and have…