What did Donald Trump do today?

He lied about the impact of his airstrikes on Iran.

In the aftermath of airstrikes on several suspected Iranian nuclear enrichment facilities in June, Trump insisted that all of them had been "OBLITERATED LIKE NOBODY'S EVER SEEN BEFORE." He also claimed that the highly enriched uranium had been destroyed, too—which is more or less physically impossible even if the actual stockpiles hadn't been moved in advance of the attack. 

When a Defense Department report released a few days later suggested that the facilities hadn't been destroyed, Trump simply repeated the claim. He issued a statement instructing the public to "take it from those who actually know," citing himself and his political allies—but not the actual experts who were telling him differently. 

But that report was, by its own admission, a low-confidence preliminary assessment. On Thursday, a much more conclusive report was issued. It said that of the three bombed facilities, two survived with only minor damage. Today, in response, Trump once again insisted that all of Iran's nuclear capabilities were "completely destroyed and/or OBLITERATED" and that it would take years to restart a bomb program.

In other words, Trump is either accusing his own military and intelligence experts of lying about a major national security concern, or lying himself, or unable to understand the truth.

Even for non-experts, the holes in Trump's story are obvious. Iran is a nation the size of the all the Rocky Mountain states put together, and with similar terrain. It has a robust nuclear energy program and domestic sources of uranium ore. Eighty years after the Manhattan Project, constructing a uranium fission bomb is not difficult in practice for a country with hundreds of thousands of trained engineers and physicists. 

The only real hurdle is refining the uranium, which is done with special centrifuges. These are small and portable and could easily have been moved from the targeted sites in advance of the attack, which Trump telegraphed. Keeping Iran from acquiring a store of those centrifuges, as well as the surplus of reactor fuel they've been refining, was the purpose of the Joint Comprehensive Plan of Action that Iran entered into with the United States and other nations.

Trump unilaterally withdrew the United States from the JCPOA in 2018, which allowed Iran to turn away international monitors and rebuild its stockpile of centrifuges.
 

Why does this matter?

• Past a certain point it doesn't matter if a president can't understand, can't remember, or can't tell the truth about something this important. 

• American national security is more important than Donald Trump's ego.