What did Donald Trump do today?

He straight up lied about Iran agreeing to a peace deal.

This afternoon, Trump declared that Iran had "agreed to everything" that he had demanded in peace talks. Specifically, he insisted that Iran had agreed to give up its stockpile of highly enriched uranium, to open the Strait of Hormuz and "never to close" it again. "This will be a great and brilliant day for the world," he told a conservative political conference audience. "Because Iran has just announced that the Strait of Hormuz is fully open and ready for business."

In reality, Iran's government has emphatically rejected Trump's claims, outright accusing him of lying to manipulate the markets and score political points at home. Iran's foreign minister announced on state television that "Iran’s enriched uranium is as sacred to us as the soil of Iran and will under no circumstances be transferred anywhere," and that the matter had not even come up for discussion.

As for the opening of the Strait of Hormuz, which is in Iran's long-term financial interest, there was a brief moment today when Iran once again signaled it was moving towards a limited, toll-based opening of the Persian Gulf to international shipping. But that immediately fell apart when Trump insisted that the United States Navy would maintain its own blockade of the Gulf. Iran's government announced that the Strait would remain open in a limited capacity, far below its normal volume, only for the duration of a 10-day ceasefire that expires at the end of the coming week.

The ships that have been stuck in the Gulf since the conflict began clearly believe Iran. A number of them broke for the Strait today, only to sharply turn back when the Iranian government announced the actual terms.

Two countries that had actually come to an agreement might spin things slightly differently for domestic political purposes—but not to the extent of one declaring peace while the other remained at war. Unfortunately for the United States, Trump has far more reason to lie than the alliance of religious hardliners and military officers that control Iran. Unlike the authoritarians he openly admires, Trump does not yet have complete control of state media, and only limited ability to inflict violence on his internal political enemies. The war has strengthened the Iranian regime's control over its population and helped it suppress internal dissent, while the disastrous and predictable outcome has greatly weakened Trump, and the United States in general.

This was the outcome that internal White House sources were trying to warn Trump of a month ago today when they said that he had blundered into letting Iran control how and if the war ended. It remains unclear to what extent Trump believes what he was saying today.

As has happened frequently during the second Trump administration, there was a sudden and anomalous spike in trading of oil futures immediately before Trump's announcement, which itself came just before markets closed for the weekend. 

Why does this matter?

• Reality doesn't change just because Donald Trump says so. 

• It's bad when a hostile foreign country can use the president's ego as a weapon against the United States.