President Trump’s tariffs were initially seen as a cudgel to force other countries to drop their trade barriers. But they increasingly look like a more permanent tool to shelter American industry, block imports and banish an undesirable trade deficit.

More than two years into the Trump administration, the United States has emerged as a nation with the highest tariff rate among developed countries, outranking Canada, Germany and France, as well as China, Russia and Turkey. And with further trade confrontations brewing, the rate may only increase from here…

Douglas Irwin, a trade historian at Dartmouth College, said Mr. Trump’s tariff battle with China was bringing about “a new status quo for the world economy.”

“If we do have this consensus that we want to isolate ourselves from China, that’s a big historic shift in U.S. trade policy,” Mr. Irwin said. “We’ve moved away from tariffs as a bargaining chip to get a better deal to tariffs as a means to an end to decouple the economies.”