In fairness to Trump, he heard that directly from China’s president (or so he says). What was he supposed to do, be skeptical of Chinese nationalist propaganda?

If you can’t trust Xi Jinping to shoot straight with you about a western-allied country within China’s sphere of influence, who can you trust?

In an interview with the Wall Street Journal last week, Trump said Xi told him during a recent summit that “Korea actually used to be a part of China.” The comments sparked outrage in Seoul and became an issue in South Korea’s presidential race, prompting the foreign ministry to seek to verify what Xi actually said.

“It’s a clear fact acknowledged by the international community that, for thousands of years in history, Korea has never been part of China,” foreign ministry spokesman Cho June-hyuck said at a briefing in Seoul on Thursday…

“This is clearly a distortion of history and an invasion of the Republic of Korea’s sovereignty,” conservative Liberty Korea Party candidate Hong Joon-pyo said through a spokesman.

Politically, that’s a bit like idly observing that Crimea contains a lot of ethnic Russians. An alarming possibility, though: Maybe Xi didn’t say that to him. Maybe Trump simply misunderstood, and now, because he seems not to realize which details he should and shouldn’t share publicly about his discussions with China’s leader, South Korea’s leadership is left to wonder erroneously whether Beijing is planning to include them in its “one China” plans a few decades from now. More from the Telegraph:

“I suspect that Mr Xi said, in effect, that Korea was part of China because it was overwhelmingly under Chinese influence historically and Mr Trump bought that,” said Rah Jong-yil, a former South Korean ambassador to both London and Tokyo.

“It shows his shocking ignorance of the situation in north-east Asia,” he told The Telegraph. “That is very disturbing to us”…

There is a growing body of nationalist thought in China that ancient Korean kingdoms were part of the Chinese empire and that modern-day nation states should similarly fall within Beijing’s exclusive sphere of influence, Mr Rah said.

If the South Koreans had any sort of troll game at all, they would have responded by claiming that Mexico’s president recently reminded them that the U.S. used to be part of Mexico. That would have been an amusing phone call between Trump and Pena Nieto.

As a Twitter pal said, what would make this even more darkly funny is if Trump started reminding everyone that China used to be a part of Japan. Does he really have no sense of the nationalist sensitivities in the region or how nervous U.S. allies there are about China’s growing power, especially after the White House ditched TPP? His tough talk towards China as a candidate might have reassured them but it’s been nothing but sunshine with Beijing since that phone call with Taiwan’s president. What looked like a looming “U.S. and Russia isolate China” long-term play by the White House during the transition increasingly looks more like a “U.S. and China isolate Russia” strategy. (Neither is likely to work, but still.) Imagine watching that play out in Tokyo or Seoul and suddenly finding Trump repeating Chinese talking points about the Korean peninsula.

Ah well. So long as he has an “armada” in the vicinity to help protect South Korea from the menace to the north, they’ll forgive him. Once they’re done forgiving him for BSing them about that armada, that is.

South Korea dismisses #Trump's remark that Korea was "part of China." pic.twitter.com/DtHa4gOSHe

— Dr. Jeffrey Guterman (@JeffreyGuterman) April 20, 2017