Win Cramer had big plans to hire several new employees this summer for his company, including a chief operating officer, but he took the job listings down after President Trump tweeted that more tariffs would hit Chinese goods in September.

Trump’s escalating trade war has spooked business executives. There’s already been a noticeable decline in business investment as corporate leaders say Trump’s tariffs and unpredictability are creating too much uncertainty, dissuading them from spending large sums on new buildings or equipment. Now there are early signs that business leaders are beginning to pull back on hiring, too.

“It’s the most frustrating time I’ve ever had running a business, and I’ve been doing this for 20 years,” said Cramer, chief executive of JLab Audio, which makes wireless ear buds and headphones that are sold at Best Buy, Target and elsewhere.

The United States had 7.3 million job openings in June, down from a peak of 7.6 million in November, according to the latest Labor Department data. While the decline is modest, economists are concerned hiring could dry up quickly as companies see no end in sight to Trump’s trade war and they look to cut costs. The reduction in job openings is also widespread across many industries, signaling how cautious companies are becoming.

“The probability of a recession in the next year has jumped,” said Sung Won Sohn, an economics professor at Loyola Marymount University and president of SS Economics. “This is a time to be cautious. Businesses are being careful about spending and hiring.”

The Trump Administration announced Tuesday that some of the new tariffs would be delayed until December 15, an effort to try to minimize the impact on the holiday shopping season, but Cramer said JLab Audio would still be hit in September.

A decrease in job openings has tended to be a signal of economic trouble, according to Labor Department research. Job openings peaked in April 2007, for example, nine months before the start of the Great Recession.

Job openings in many industries have declined since November, including the information sector, financial services, transportation and warehousing, and hotels and food service, suggesting wide concern about future growth. Actual hires also have slowed this year, with average monthly job gains falling to 165,000 a month, down from 223,000 a month last year.

Labor Department data shows what has happened to job openings only through June, before Trump’s latest tariff threat on China, which has triggered a stock market sell-off, but anecdotal evidence suggests more companies might be hesitating to post jobs.

Cramer has lived in the midst of the trade whiplash all summer. His business was thriving in the spring and he wanted to bring on three new employees, a significant investment for a company with 35 workers. He drafted job descriptions for two entry-level customer service jobs and the COO position, but he put everything on hold in June after trade talks between the United States and China broke down.

He moved forward again after Trump and Chinese President Xi Jinping appeared to negotiate a truce at the end of June on the sidelines of the G-20 summit in Japan and even began interviewing candidates. But then Trump tweeted Aug. 1 that he would move forward with a 10 percent tariff on an additional $300 billion of Chinese imports, meaning nearly all goods coming from China to the United States would have a hefty added tax.

“We put hiring on hold again after the tweet came out,” Cramer said. “We’re in a business where we need certainty. We can’t make investments because we don’t know if those investments will have to be absorbed or dissolved.”

JLab Audio will face tariffs in September, just as goods are starting to flow heavily from China to the United States for the prime holiday shopping season. Manufacturing elsewhere is not an option, he says, given his company’s size and the fact that China dominates a lot of consumer electronic production.

Economists fear this latest round of tariffs will impact consumers, the back bone of the U.S. economy, much more than prior rounds since this tax would fall on popular items like iPhones, laptops, shoes and baby products. Consumer spending makes up nearly three quarters of the economy, and people will spend less if prices rise and they see fewer “we’re hiring” ads around their community.

On Monday, investors ran to the safety of U.S. government bonds, sending the yield on the 30-year Treasury bond down to close to an all-time low, a signal of just how alarmed many are about what’s ahead for the U.S. and global economies. The bond yield has been falling since November of last year.

The White House has argued that costs to American consumers will be minimal since China has devalued its currency to keep Chinese products cheap, but Cramer and others say the devaluation is modest compared with the size of the tariff and many contracts with Chinese firms priced in dollars.

“The proposed 10 percent tariff on $300 billion of low grade Chinese imports is effectively a major hidden tax on U.S. consumers. A kamikaze attack on your own aircraft carrier,” said Brian Bethune, chief economist at Alpha Economic Foresights and a lecturer at Tufts University.

On a call last week with reporters, several chief executives of other companies likely to be hit by the new tariffs indicated they are also skittish about making investments right now and they would likely lay workers off if Trump moves forward with the tariffs.

“I believe protracting the trade war has significantly increased the risk of a potential recession,” said Wade Miquelon, president of Joann Stores, which specialize in fabrics and crafts.

Small and midsized companies have already locked in contracts for the holiday season with the big retailers, making it difficult to raise their prices, so they are more likely to resort to layoffs to manage costs.

“If we endure 10 percent tariffs, we would reduce our head count by 10 percent. The money has to come from somewhere,” said Jay Foreman, chief executive of Basic Fun! Toys, which employs 110 workers, mostly in Florida.