Over the weekend, Donald Trump made good on his promise to impose trade barriers on key US trading partners — with the exception of Mexico, whose tariffs were delayed at the last minute. Citing the influx of narcotics and “illegal aliens,” the president announced a 25 percent tariff on goods from Mexico and Canada (with a 10 percent carve-out for Canadian energy imports), while Chinese goods received a blanket 10 percent in addition to the levies already in place on imports from that country.

As economic policy tools, these measures are misguided. In addition to heightening the economic stress of domestic households, they will likely fail to permanently alter the trade deficit, the reduction of which is central to Trump’s neoprotectionist ambitions.

The geopolitical logic is as unsound as the economic one is unclear. The discrepancy between the tariffs on the United States’ immediate neighbors and the additional ones on China, which the elites of both parties identify as their main geopolitical rival, raises the question of what this opening salvo of the trade war is supposed to achieve.