The trade war promised by President Donald Trump stepped up a gear overnight, with 25% tariffs on goods from Mexico, Canada, and an additional 10% on China taking effect. No one was really sure that it would actually happen—a month ago,

Imports to the U.S. from Canada and Mexico are now to be taxed at 25%, with Canadian energy products subject to 10% import duties.

Beijing imposed broad tariffs on imports of American food and said that 15 U.S. companies could no longer buy from China without special permission.