Kim Jong-un and President Trump understand each other perfectly. Walking away from the Iran deal was, among other things, a public message from Mr. Trump to Mr. Kim that we can act just as aggressively and disingenuously as he can, and that he, Mr. Kim, is now negotiating with realists.

And isn’t it interesting that Mr. Trump is helping his pal Xi Jinping, president of China, avoid the bankruptcy of ZTE in exchange for what? Perhaps more pressure from China on North Korea?

Mr. Kim’s response was that he can be just as unpredictable as Mr. Trump. This is all standard preliminaries before the big event.

GEORGE SPENCERKINDERHOOK, N.Y.

To the Editor:

Of course North Korea is threatening to cancel the summit meeting with President Trump because the United States and South Korea are carrying out typical joint drills on the peninsula. Did we really expect anything else?

North Korea is working closely with the Chinese to foster an outcome that results in a United States withdrawal from South Korea, while giving up as little of its nuclear program as possible. Meanwhile, 300,000 Chinese troops reportedly were sent to the North Korean border, ready to uphold their treaty obligation to respond if the United States strikes North Korea.

Don’t be fooled, folks. Kim Jong-un has no intention of relinquishing his nuclear arsenal, and given China’s role, it has a much stronger hand than most imagine.

Mr. Trump should cancel the summit, sending a strong signal to Mr. Kim that if he isn’t ready to give up his arsenal, the United States isn’t ready to talk.

DAN SMITH, DETROIT

A version of this article appears in print on , on Page A22 of the New York edition with the headline: The Motives Behind the Trump-Kim Maneuvers. Order Reprints | Today’s Paper | Subscribe