AS AN example of all that is wrong with Donald Trump’s view of trade, the probe he has ordered into the steel industry is particularly hard to beat. If it results, as seems to be the plan, in blanket punitive tariffs slapped on steel imports, the consequences would be dire: the American economy would be hurt by a rise in the price of an essential material; it would invite retaliation that would cost American jobs, not save them; and the underlying problem—massive global steel overcapacity—would persist.

For Trumpists, steel is an emblem of their country’s descent from greatness. Ever since the 1960s, when production peaked at 168m tonnes a year, the industry has been in decline. Today it makes half as much as 50 years ago and employs just a third of the workers. Steelmakers have long blamed foreign rivals for their woes and lobbied hard for protection. So Mr Trump is not the first president to try to shield the industry from foreign competition. In the 1980s Ronald Reagan signed a series of agreements to limit imports. In 2002 George W. Bush imposed tariffs of up to 30%. Back then the bogeymen were steelmakers in Europe and Japan; now it is China, where a glut of steel has squashed prices.

Cheap steel, however, is a boon to many producers as well as to consumers. Higher prices would hit firms that use the metal, such as carmakers. Mr Bush’s…Continue reading