In the escalating economic showdown between the United States and China, President Trump is trying to put American shoppers first. The administration did not place tariffs on necessities like shoes and clothes, and mostly spared smartphones from the 25 percent levy on Chinese goods announced this week.

But by shielding consumers, Mr. Trump has put American manufacturers — a group he has championed — in the cross hairs of a potential global trade war. If the measures stand, along with China’s retaliatory tariffs, they could snuff out a manufacturing recovery just beginning to gain steam.

“If you want to spare the consumer so you don’t get this massive backlash against your tariffs, then there goes manufacturing, because that’s what’s left,” said Monica de Bolle, an economist at the Peterson Institute for International Economics. “The irony is, you cannot spare manufacturing from anything because manufacturing is globally integrated. The sector sources its parts and components from all over the world.”

That intricate supply chain often runs directly between the two countries, sometimes in both directions. Chinese factories make wing panels and doors for Boeing’s Next Generation 737 planes, which are assembled by union workers in Renton, Wash. General Motors makes its Buick Envision, a sport-utility vehicle, in Shandong Province, and sells it to American consumers. Construction workers in Denver use building materials manufactured in China, made in part from ethane gas produced in Texas.