In what is being called the most momentous foreign policy move of Donald Trump’s presidency, the president announced on May 8, 2018 that he’s withdrawing the United States from its historic 2015 nuclear accord with Iran. The end of the nuclear deal means a new beginning for economic sanctions against the country—sanctions that, over the decades, have cratered Iran’s economy and destabilized relations throughout the Middle East.

Technically, the United States and Iran have never been at war. But by imposing unilateral sanctions, the U.S. has long wielded money as a weapon in a shadow war that’s been raging since 1979. Here’s how sanctions went from punitive measure to status quo: 

The Iran hostage crisis led Jimmy Carter to mount the first U.S. sanctions against Iran

The history of American sanctions against Iran began with a bang when a group of Iranian students stormed the American embassy in Tehran on November 4, 1979, taking more than 60 United States citizens hostage and sparking an international crisis. The 444-day-long hostage crisis tanked Jimmy Carter’s presidency, ushered in a new political era for Iran, and helped skyrocket Ayatollah Ruhollah Khomeini, a revolutionary cleric who objected to United States interference, to international significance. ...