The personal touch, by the way, distinguishes Trump’s outreach to North Korea from Barack Obama’s to Iran. The Iranian regime is a group project, with many leaders with ideological and economic interests in continuing hostility to the United States. Obama’s hope that he could change its outlook clearly went unrealized.

Kim Jong Un’s regime, in contrast, appears highly personal, one in which the leader can order the sudden deposition and death of an uncle who is a key official. That regime’s behavior, Trump is betting, will change if he can change the mind of just one man.

Of course, this may not work out. But the argument is that nothing else has, and with North Korean nukes now poised to hit the West Coast, it’s worth trying. “The world is safer than it was a week ago,” writes the veteran Washington Post foreign correspondent David Ignatius, “and Trump is getting some deserved global applause.”