This showed up as a response to me-
"I'm still trying to figure out how he went from praising the Tweet, to calling it boneheaded, to whining at all the people who considered it boneheaded in the first place.
"Hey all you people who thought this was a dumb Tweet five minutes before I called it a dumb Tweet - you're all way too thin-skinned and sensitive!""

It is a dumb tweet-he referenced Japan/US history long ago which made sense as to why that reference but he never should have tweeted it.