Small businesses in the U.S. are succumbing to a growing chorus of warnings about a coming economic slowdown or recession, according to a new survey, with a key gauge of confidence falling last month to its lowest in five months. 

The National Federation of Independent Business, an association representing small firms, said Tuesday that its optimism index slid by 1.6 points last month to a reading of 103.1, the lowest in five months. Economists had expected a decline of just 1.2 points.

The drop signals that small-business owners, who were ebullient in the wake of President Donald Trump's election thanks to his promises of tax cuts and looser federal regulations, are now tempering their expectations as economists say the administration's trade war with China is contributing to a global downturn. 

"The manic predictions of recession are having a psychological effect and creating uncertainty for small-business owners throughout the country," Juanita Duggan, the association's president, said in a statement.

The disappointing report comes as a growing number of surveys show waning confidence among business executives, investors and consumers alike. A monthly survey released Monday by the Federal Reserve Bank of New York showed that consumers last month saw a higher perceived probability of losing their jobs, with falling expectations for incomes and home prices. 

Based on the business association's latest survey results, small firms invested in new factories, equipment and technology at a faster pace in August than in July, but they now appear reluctant to make major spending commitments.

The timing jibes with a retreat in U.S. stocks last month from July's record levels, after Trump's proposed tariff increases on imports from China triggered a series of tit-for-tat retaliatory measures from the Asian country. Economists say a lack of certainty over future tariff levels has sparked such uncertainty among business executives that they've become less willing to commit to big expansion plans.  

"The imposition of new tariffs on imported Chinese consumer goods and the promise of increases in existing tariffs can't have helped," Ian Shepherdson, chief economist at the forecasting firm Pantheon, wrote in a note to clients. 

Yields on 10-year U.S. Treasury bonds are trading below interest rates in short-term money markets -- an unusual dynamic that often precedes a recession, since it sends a signal to investors and banks not to lend money for long periods of time.    

According to Duggan, the association president, small businesses "continue to invest, grow and hire at historically high levels, and we see no indication of a coming recession."

The Washington-based group is an active advocacy and lobbying force in Washington, with its political-action committee giving some 98% of contributions in the 2018 election cycle to candidates from Trump's Republican Party.

In the statement, the organization decried the "doom and gloom narrative that's hampering expectations."  

"Job creation accelerated, positive earnings trends improved, and quarter-on-quarter sales gains remained strong," according to the statement. 

Even so, the group acknowledged: "Fewer owners said they expect better business conditions and real sales volumes in the coming months."  

Shepherdson, the economist, said the small-business optimism index can be heavily influenced by the performance of the stock market. 

But the takeaway is clear, he said: "Small firms don't like the trade war." 

Or maybe from the perspective of the economy's cheerleaders: "You shouldn't have read this story."