Tariffs are Trump’s favorite foreign policy tool. The Supreme Court could change how he uses them

President Donald Trump speaks during an event to announce new tariffs in the Rose Garden at the White House. (AP)

President Donald Trump sees tariffs or the threat of them as a powerful tool to bend nations to his will. He has used them in an unprecedented way, not only as the underpinning of his economic agenda, but also as the cornerstone of his foreign policy in his second term.

He has wielded the import taxes as a threat to secure cease firesfrom countries at war. He has used them to browbeat nations into promising to do more to stop people and drugs from flowing across their borders.

He has used them, in Brazil’s case, as political pressure because its judicial system prosecuted a former leader who was a Trump ally, and in a recent blowup with Canada, as punishment for a television