Should the trade war seriously damage the Chinese economy, however, the world would lose its biggest single driver of economic growth in recent years. A lengthy tariff conflict might also force even more American companies to look for other places to set up their factories. That could be a complicated and expensive process that dents their productivity for years to come.

Both sides are considering ways to help businesses endure the fight. Mr. Trump has boosted aid to farmers and contemplated tax cuts. But thanks to the Chinese government’s tight control over the economy, Beijing has more options, including dramatic steps such as flooding the financial system with money or ramping up government spending.

On Tuesday, the central government announced measures aimed at empowering the country’s shoppers, including discounts for appliance purchases and a weakening of traffic-related restrictions on the sale of new cars . It is trying to find new markets for China’s factories, including by trying to reach a trade deal covering most of eastern and southern Asia before November.

The government has also been trying to directly help small businesses slammed by both the trade war, which has hurt exports to the United States, and the debt reduction campaign, which has pinched lending. In May, Zhejiang Province in eastern China unveiled a $30 billion plan to cut taxes and regulatory costs for small businesses.

Still, signs of strain are not hard to find. In the city of Huzhou, in Zhejiang, local officials in December surveying the impact of the trade war found a company called Tianzhen Bamboo Flooring that was laying off workers and trying to open new markets in Europe and Canada. A person at the company who answered the phone this week as Ms. Zhang confirmed that some workers were cut, and that Tianzhen had not had much luck with new markets so far.