This is a first for the Trump presidency: the first formal presidential retraction of a presidential untruth.

President Trump tweeted a warning to James Comey: The fired FBI director had better hope that no “tapes” existed that could contradict his account of what happened between the two men. Trump has now confessed that he had no basis for this warning. There were no such tapes, and the president knew it all along.

The tweet was intended to intimidate. It failed, spectacularly: Instead of silencing Comey, it set in motion the special counsel investigation that now haunts Donald Trump’s waking imagination.

But the failed intimidation does have important real world consequences.

First, it confirms America’s adversaries in their intensifying suspicion that the president’s tough words are hollow talk. The rulers of North Korea will remember the menacing April 4 statement from the Department of State that the United States had spoken enough about missile tests, implying that decisive actions lay ahead—and the lack of actions and deluge of further statements that actually followed.