Diplomacy often is the art of saying things you don’t mean, in order to put an opponent off guard or ingratiate him to you personally. Let us hope President Donald Trump was engaged in such a manipulative technique in a tweet he issued Wednesday.

It appears Trump and North Korean dictator Kim Jong Un will meet sometime during the next few weeks, possibly in China. The topic will be U.S. insistence that Kim get rid of his nuclear weapons and, probably, his long-range missiles.

On Wednesday, Trump tweeted that “there is a good chance that Kim Jong Un will do what is right for his people and for humanity.”

No, there is not.

Like his father and grandfather before him, Kim will do what he believes is right for himself and his heirs. Millions of North Koreans have perished because the Kim dynasty saw them as threats or as expendables to be sacrificed to the good of the regime.

Whether Trump can convince Kim dialing back his aggressiveness is in his best interest is one thing. But believing he is motivated by anything else would be a serious mistake.