What did Donald Trump do today?

He folded on his protection racket idea in less than a day.

On Sunday, Trump falsely declared the Strait of Hormuz open. It is not: virtually no ships are passing through, because Iran's threats to attack them are credible.

On Monday, Trump repeated that lie, and then insisted (apparently without telling anyone else) that he would somehow be imposing a 20% surtax on cargo shipped through the Persian Gulf to cover "all costs necessary to do the job of providing safety and security." He didn't say when or how he intended to start providing safety and security, but any plan that would affect Iran's ability to launch drones or missiles at ships would involve physically occupying Iran, a country of 92 million people.

Today, less than a day after announcing the protection racket idea, he backed down, citing "deals" he'd supposedly made for foreign investment. No Gulf nation has confirmed having spoken with Trump.

Trump often announces vague and unenforceable "deals" he's made with other countries for investment in the United States. Over and over and over and over and over and over and over again, Trump has bragged about collecting IOUs in exchange for policy or trade concessions of real value, but it's hard to point to a single dollar of foreign investment that resulted that wouldn't have happened because of normal market opportunities.

Why does this matter?

• It's a problem for the United States that nobody believes anything its president says. 

• A competent dealmaker wouldn't get taken in by people offering meaningless promises so often.