Never have the U.S. and Chinese economies been more interdependent than they are today. Never has the value of the bilateral trade and investment relationship been greater. Never has the precarious state of the global economy required comity between the United States and China more than it does now. Yet, with Donald J. Trump ascending to power on a platform of nationalism and protectionism, never have the stars been so perfectly aligned for the relationship to descend into a devastating trade war. Bilateral trade frictions are nothing new. Over the years they ebbed and flowed, but the...