The president has also said he wants to restore domestic manufacturing, reduce the trade deficit, and stop the country’s foreign trading partners from ripping it off. His is a zero-sum, mercantilist understanding of the global economy, in which trade deficits are a kind of bloodletting and the United States is strongest when it produces what it consumes. But the vast majority of economists, politicians, and business leaders—including many in the Trump administration itself—believe that fair trade is positive-sum, and that trade surpluses are often nothing more than indications that one country is more capable of producing a given item. “There are lots of good reasons why you’d want to run a trade deficit,” Kevin Hassett, Trump’s top economist, recently argued. Given these dynamics, bringing manufacturing back would not necessarily make America great again, and a smaller trade deficit with China would not necessarily mean a stronger American economy.

Nor would it be easy, or desirable, for American companies to end production in China and make more things in America. Global supply chains are intricate, investment-intensive, border-spanning webs. Uprooting them would come with a tremendous cost, and would mean diverting American resources to producing low-value, low-tech goods. Trump’s trade actions “are a prime example of 20th century tools aimed at the knowledge-embodying trade flows of the 21st century,” Mary Lovely of the Peterson Institute for International Economics and Yang Liang of Syracuse University have argued.