So, the trade war is on. And what a stupid trade war it is.

My regular column for tomorrow is about health care, but I felt I needed to weigh in on this idiocy, and not just on Twitter.

The official – and legal – justification for the steel and aluminum tariffs is national security. That’s an obviously fraudulent rationale, given that the main direct victims are democratic allies. But Trump and co. presumably don’t care about telling lies with regard to economic policy, since that’s what they do about everything. They would see it as all fair game if the policy delivered job gains Trump could trumpet. Will it?

OK, here’s the point where being a card-carrying economist gets me into a bit of trouble. The proper answer about the job-creation or -destruction effect of a trade policy – any trade policy, no matter how well or badly conceived – is basically zero.

Why? The Fed is currently on a path of gradually raising interest rates, because it believes we’re more or less at full employment. Even if tariffs were expansionary, that would just make the Fed raise rates faster, which would in turn crowd out jobs in other industries: construction would be hurt by rising rates, the dollar would get stronger making U.S. manufacturing less competitive, and so on. So all my professional training wants me to dismiss the jobs question as off-base.