China’s proposed new tariffs cover a significant chunk of what it buys from the United States. The protections on the $50 billion of goods announced on Wednesday, together with those on the $3 billion worth of products that Beijing unveiled earlier this week in retaliation for American tariffs on global steel imports, account for about a third of China’s American imports.

By contrast, because the United States imports significantly more from China, tariffs on the same amount of products make up roughly one-ninth of its Chinese imports. That gives the United States more room to find other Chinese products to target.

Even as Chinese officials struck a defiant tone on Wednesday, they still said they wanted to avoid escalating the conflict.

“China’s attitude is clear,” Mr. Zhu, the vice minister of finance, said. “We don’t want a trade war because a trade war would hurt the interests of both countries.”

China could still fight back in other ways. Its control over its domestic economy and news media, and its homegrown internet, give it a strong hand in controlling public opinion and minimizing the potential impact on its consumers. In the past, China has mobilized its vast ranks of consumers to turn up their noses at products from Japan, the Philippines and South Korea during political disputes, though getting Chinese consumers to stop buying iPhones and Chevrolets could be trickier.

The two sides are clashing with the future in mind. President Trump instituted his latest round of tariffs against China while citing Beijing’s government-driven efforts to retool the country’s economy to focus on the technologies of the future. Known as the Made in China 2025 program, the plan specifies efforts to build up cutting-edge industries like robotics, aerospace and electric cars.

Many companies in Europe and the United States say they fear the program will create state-supported competitors, an argument that has won backing in the Trump administration. Some companies say that Beijing finds ways to force them to hand over technology if they want to sell their wares in China, an allegation that Chinese officials dispute.