Why Trump's admission that he made stuff up to Justin Trudeau is particularly bad

US President Trump boasted to donors that he told Canada's prime minister that the US has a trade deficit with Canada, despite having "no idea" if that was true. Photo / AP

In a fundraising speech on Wednesday, President Trump admitted once and for all that he just makes stuff up. The man who has racked up more than 2000 false and misleading claims as president said he insisted to Canadian Prime Minister Justin Trudeau that United States runs a trade deficit with Canada — despite having "no idea" whether that was the case. (Surprise! It's not.)

"I said, 'Wrong, Justin, you do.' I didn't even know," Trump said. "I had no idea. I just said, 'You're wrong.' You know why? Because we're so stupid."

None of this is hugely surprising. Trump utters way too many falsehoods for it to be a coincidence. And we've seen over and over again — particularly most recently in meetings with lawmakers about guns and immigration — that Trump simply doesn't do his homework beforehand. He generally doesn't seem to have even a cursory understanding of what Congress is up to or about the underlying policies.

But the fact that Trump would make up this particular fact is especially remarkable and ominous.

The first reason is that this is perhaps the one issue Trump has focused on for decades: trade. It would be more understandable for him to make things up on guns and immigration, but trade is supposedly the issue on which Trump has been entirely consistent for many years. The idea that other countries are taking advantage of the United States was a talking point long before he became a politician.

Trump for years has talked about how the North American Free Trade Agreement is such a bad deal. And he threatened Canada with new steel and aluminum tariffs, before he decided to exempt them, for now, as long as the NAFTA negotiations go his way. Yet he didn't even know that the United States runs a trade surplus with Canada!? If he doesn't have that basic a level of background knowledge on an issue he apparently cares deeply about, what does he study?

The second reason is that it was a rather pointless invention. Trudeau knows the truth: He has been involved in policymaking for years and knows these things, because it's very important to his job as a world leader. Why Trump would feel the need to make something up that is of such consequence to Trudeau doesn't even make sense for strategic reasons. It's not as if Trump was going to pull one over on the prime minister and have the Canadians suddenly cave on NAFTA negotiations.

The final part of this is what it says about Trump's brand of diplomacy. This isn't the first time we've got a glimpse behind the curtain. Early in his presidency, the Washington Post obtained transcripts of his calls with the leaders of Australia and Mexico.

Trump's call with Australian Prime Minister Malcolm Turnbull turned contentious after Trump became enraged by an agreement the Obama administration made with Australia to take some refugees. Trump didn't seem to have any understanding of the agreement of Australia's policy of not accepting refugees who arrive by boat.

What happens if Trump takes this approach — or the one from the meetings on guns and immigration — to his meeting with North Korean leader Kim Jong Un? Can a guy who can't be bothered to understand the basics before talking to foreign leaders and lawmakers do the kind of homework required for very sensitive and complicated negotiations involving nuclear programs? And what if he doesn't even try? What if he decides to wing it, as he did with Trudeau?

Thus far, Trump has shown no signs that he thinks that style isn't working. And apparently, it's still very much a part of his international diplomacy.

• Aaron Blake is senior political reporter for The Fix. A Minnesota native, he has also written about politics for the Minneapolis Star Tribune and the Hill newspaper.