At the recent Brussels summit, the leaders of all 27 European Union states called on the European Commission to expand the bloc’s trade defence toolbox against “global macroeconomic imbalances”, widely understood to refer to China’s so-called overcapacity. Measures under discussion include mechanisms for sector-wide tariffs and other restrictions in industries such as chemicals and green technology. Europe, long a critic of Washington’s Section 301 tariffs, is now considering instruments that...