Trade Wars Are Class Wars: How Rising Inequality Distorts the Global Economy and Threatens International Peace by Matthew C. Klein and Michael Pettis Yale University Press, 2020, 288 pp. A few years before the global financial crisis of 2008, future Federal Reserve Chairman Ben Bernanke popularized the notion that the world was divided into trade surplus countries like China and trade deficit countries like the United States. Echoing John Maynard Keynesâs trade destabilization theory, Bernanke argued that this imbalance was a significant cause of global instability. But whereas Keynes saw instability as a normal product of global trade, the effects of which would be mitigated by international financial agreements putting limits on surpluses and deficits, Bernanke laid the blame squarely at the doorstep of the East Asian and German economies.