How One 1977 Law Became the Center of a Global Trade Battle

A once-obscure 1977 law has become the unlikely centerpiece of a global trade battle, culminating in a federal court ruling that Donald Trump’s use of it to impose tariffs was illegal. The decision highlights the contentious repurposing of the International Emergency Economic Powers Act (IEEPA) from a foreign policy tool to an instrument of economic protectionism.
Originally, Congress passed the IEEPA to give presidents the authority to respond to “unusual and extraordinary” foreign threats, such as by freezing the assets of hostile regimes or terrorist groups. Its use by President George W. Bush after the 9/11 attacks to block terrorist financing is a textbook example of its intended function.
However, the Trump administration controversially argued that chronic U.S. trade deficits constituted such a threat, using the IEEPA to bypass Congress and impose a 10% baseline tariff on most imports. This novel interpretation was challenged immediately, with critics arguing it was an abuse of the law’s original intent.
The appeals court has now sided with the critics, ruling that the IEEPA does not mention tariffs and was not designed for broad economic management. The decision effectively returns the law to its original national security context and sets up a Supreme Court fight over this dramatic expansion of its use.