Donald Trump's sudden decision to send no official representative to this year's G20 meeting has upset planning and is making it impossible to say if the upcoming meeting will have any real impact. The possible absence of representatives from Russia makes things even more uncertain.

Decades ago, back when Gerald Ford was the US president and New York City was on its knees financially, the Ford administration declined to back financial aid and loan guarantees for the then-beleaguered Big Apple, a city that was teetering on the precipice of bankruptcy. The headline on the New York Daily News front page was perfect in its simplicity. It read: "Ford to City: Drop Dead."

The current incumbent president of the United States, Donald Trump, has effectively dropped the same line on the G20 and South Africa, announcing there would be no, zero, nada official US presence at the global meeting in Johannesburg, now less than two weeks away.

His social media announcement -- in the bizarre way US government announcements come along these days -- reads:

"It is a total disgrace that the G20 will be held in South Africa. Afrikaners (People who are descended from Dutch settlers, and also French and...