About the Law That Trump Is Wielding to Impose Tariffs: QuickTake

U.S. President Donald Trump looks set to turn to a Cold War-era law to stem the flow of steel imports, part of a campaign pledge to save American industrial jobs. He is on the verge of deploying a weapon known as the "nuclear option" or the "big sledgehammer," a little-used part of 1962 trade legislation, to counter cheap imports that he argues put national security at risk by weakening the domestic steel industry. Such heavy tools can prompt a furious response from other countries, triggering complaints to the World Trade Organization.

Section 232 of the Trade Expansion Act of 1962 allows the president to adjust imports without a vote by Congress should the Department of Commerce find evidence of a national-security threat from foreign shipments. Commerce Secretary Wilbur Ross, a former steel tycoon, says such a threat exists, and Trump says he plans to levy tariffs of 25 percent on imported steel and 10 percent on imported aluminum.