Already, a key measure of business capital spending in the United States, “fixed nonresidential investment,” was in negative territory in the second quarter. And in the nation’s factories, the rate of growth has slowed for five consecutive months, according to the Institute for Supply Management’s index. Although this measure still showed growth, the July reading was the weakest since August 2016.

The trade war between China and the United States is a big part of the reason. The conflict has made it difficult for many global firms to plan their operations — and in some cases, it may lead them to sit on their hands rather than invest. The American strategy has been more successful at escalating trade tensions than in resolving them, so companies do not know whether tariffs will go away soon or will be a continuing cost of doing business.

“The president says we’re going to get a great deal and a great deal soon, but he’s been saying that for over a year,” said Phil Levy, a former trade official in the George W. Bush administration and a chief economist at Flexport, a freight forwarder that works with many companies involved in international trade. “You end up paralyzed. You have to make plans, but there is risk all over the place, so businesses get cautious and hold back on investment.”