Since the 1960s, tariffs — or import taxes — have emerged from negotiations between dozens of countries. Trump wants to seize the process. “Obviously, it disrupts the way that things have been done for a very long time,

South Korea's free trade agreement with the United States could help mitigate its exposure to reciprocal tariffs threatened by U.S. President Donald Trump, economists at two major investment banks have said.

The president’s plan for reciprocal tariffs sounds good in theory. But there was a reason the United States abandoned the approach a century ago. The gains would be few and the costs enormous.