CAMBRIDGE – U.S. President Joe Biden’s economic and foreign policies may represent a sharp departure from those of his predecessor, Donald Trump. But when it comes to relations with China, Biden has largely maintained Trump’s tough line – refusing, for example, to reverse Trump’s tariff hikes on Chinese exports and warning of further punitive trade measures. This reflects the widespread hardening of U.S. attitudes towards China. When Foreign Affairs magazine recently asked leading U.S. experts whether American “foreign policy has become too hostile to China,” nearly half of the respondents (32 out of 68) disagreed or disagreed strongly – suggesting a preference for an even tougher U.S. stance toward China. For economists, who tend to view the world in positive-sum terms, this is a puzzle. Countries can make themselves and others better off by cooperating and by shunning conflict. The clearest application of this principle is the gains from trade that countries