Even some retired officials have said they believe that the trade war could have positive effects. Long Yongtu, who led the negotiations for China’s entry into the World Trade Organization, said at a forum last month that trade friction could be “a good thing.”

It could be “a healthy pressure that pushes China to move forward,” he said.

The chances that Mr. Trump alone can change China's ways are exceedingly slim. The Communist Party risks looking weak if it agrees to too many of his demands. True reform would have to come from inside.

“We can’t count on the external force to save China,” said Wang Gongquan, a billionaire liberal activist and former venture capitalist. He was among the first group of people who were detained or jailed after the party intensified the crackdown on dissent and civil disobedience six years ago.

“Changes will only come,” Mr. Wang added, “when responsible people inside and outside the government push for it together.”

Still, the hopes about Mr. Trump acknowledge the role the outside world has played in China’s gradual opening over the past four decades. Since the end of the Cultural Revolution, the Communist Party has largely been a reluctant reformer, often pushed and lured by internal and external forces.

Even some in the Trump administration seem to be hoping that internal voices will speak up. In an interview with National Public Radio, Robert Lighthizer, Mr. Trump’s top trade negotiator, was asked about the likelihood that the trade war would lead to changes in China.

“You have to start with the proposition that there are people in China who believe that reform is a good idea,” Mr. Lighthizer said. “And you have to believe that those people are at a very senior level.”