Spare a thought for the unhappy people who have to deal with Traveling Donnie from Queens. They’ve been up nights trying to work out how to do it without setting off a war or indictments or global disgrace.

Embassies in Washington trade tips and ambassadors send cables to presidents and ministers back home suggesting how to handle a mercurial, strong-willed leader with no real experience on the world stage, a preference for personal diplomacy and a taste for glitz.

Oh if only that were all. There’s also the profound stupidity, the lack of control, the vanity and narcissism, the dishonesty, the rudeness, the total ignorance of history, politics, economics, and everything else, the temper, the vulgarity…to name a few.

After four months of interactions between Mr. Trump and his counterparts, foreign officials and their Washington consultants say certain rules have emerged: Keep it short — no 30-minute monologue for a 30-second attention span. Do not assume he knows the history of the country or its major points of contention. Compliment him on his Electoral College victory. Contrast him favorably with President Barack Obama.

In other words treat him like a toddler not yet out of diapers. How shaming it is.