New Delhi, April 20 -- You might be able to think of a dozen ways through which a public backlash might compel Donald Trump, the President of the United States, to back down on his tariffs imposed on Chinese goods. But if I were to ask you to imagine the kind of pressures that would push Xi Jinping, the general secretary of the Communist Party of China, to do likewise, you will probably come up with a vague idea, if any at all.

That does not mean he is not under pressure. It only means that the politics of the United States is a lot more transparent. Both sides are under pressure. The next several weeks will be both a contest of which side can withstand greater pain and how effectively that pain is transmitted through their political pro...