Remember last month, when an agreement between the United States and Mexico left the world thinking we were on the brink of a radical rewriting of the North American Free Trade Agreement?

Things haven't quite gone to plan. With a touted Sept. 30 deadline for an accord just days away, U.S. President Donald Trump went on a tirade Wednesday about his dislike of his Canadian interlocutors and turned down a meeting with Prime Minister Justin Trudeau.

That's a decent framework for thinking about the prospects of a mooted Japan-U.S. trade deal announced by the White House within hours of Trump's trash-talking.