India, March 14 -- Donald Trump's return to the White House has ushered in a new era of American trade policy, one that represents a fundamental break from the past-including his own first term. The so-called "tariff wall" that Trump intends to build around the US is not just a more aggressive version of his transactional first-term policies. Rather, it represents a far more ambitious effort to reshape the global economic order and America's place in it, driven by a president significantly less deterred by consequences than last time.

The first bricks of this tariff wall were laid on March 4 with the imposition of 25% tariffs on imports from Canada and Mexico that had been initially threatened in early February and delayed at the last mi...