Eighteen months into Donald Trump’s term, the world is having trouble coming to grips with the most unconventional American president ever. Still, he is neither a bad dream from which the U.S. will soon wake up, nor a fool to be ridiculed.

For someone his critics say is a compulsive liar, Mr. Trump has been remarkably true to his word. Especially compared with his predecessor, he doesn’t moralize. It’s classic Trump to be openly exasperated by the Group of 7’s hand-wringing hypocrisy. Unlike almost every other democratic...