Nixon answered this question for China in three concise answers: Build up their world credentials. Taiwan. Get the U.S. out of Asia.

Mr. Trump might also reduce North Korea’s concerns to three points:

1. Security

Mr. Kim’s top priority is the security of his nation and the survival of the totalitarian regime that he inherited from his father and grandfather. He has said this is why he needs a nuclear arsenal: to deter the United States from attacking North Korea and attempting to overthrow him, as some in Washington have advocated.

But he has also committed to denuclearization, as long as the North can be guaranteed of its security. That is one reason a formal peace treaty ending the Korean War is under discussion. It could include assurances from both China and the United States and might lead eventually to the withdrawal of American troops from South Korea.

2. Respect

If Mao was interested in China’s “world credentials,” Mr. Kim may be more interested in building up his reputation at home.

Being treated as an equal by Mr. Trump confers prestige on Mr. Kim that he can use to strengthen his grip on power.