US President Donald Trump is using tariffs to reset America’s relationship with the rest of the world, upsetting a global norm that has lasted for decades. Many of his supporters hail it as a paradigm shift — much like Richard Nixon’s decision to abandon the gold standard on August 15, 1971, which shocked the world and reshaped the international monetary system. But this is not the first time the United States has delivered a jolt to the global trade order.