Trump’s Tariffs Could Put the Supreme Court in a Major Bind

At issue is the administration’s interpretation of the International Emergency Economic Powers Act, which the White House cited as the source of the president’s authority for the myriad tariffs he has imposed this year. Congress enacted IEEPA in 1977 as a comprehensive update of various laws that since the 1910s had allowed presidents to regulate some aspects of international trade, initially during wartime and later during national emergencies.

Under IEEPA, presidents have broad powers to regulate foreign currency exchanges, investigate and suspend international bank transfers, and to “investigate, block during the pendency of an investigation, regulate, direct and compel, nullify, void, prevent or prohibit” any foreign property sales or transactions within U.S. jurisdiction. These powers can only be invoked, according to the statute, to “deal with any unusual and extraordinary threat … to the national security, foreign policy, or economy of the United States” that is at least partly foreign when the president declares a national emergency.

What counts as a “national emergency,” however, is entirely up to the president’s discretion. Congress may have originally intended the Cold War–era law to be used against serious threats to national security from foreign adversaries. Trump has interpreted it far more loosely to target some of the United States’s closest allies and trading partners. When, during Trump’s first term, then-Canadian Prime Minister Justin Trudeau asked him about the national-security rationale for steel tariffs against Canada, Trump reportedly replied, “Didn’t you guys burn down the White House?”—a reference to the War of 1812.