What did Donald Trump do today?

He either forgot or didn't know about about his proposed Iran nuclear deal.

In 2015, the United States and five other countries entered into an agreement with Iran known as the Joint Comprehensive Plan of Action, or JCPOA. It allowed for on-site inspection of Iranian nuclear energy plants and other sites to verify that Iran had halted its nuclear weapons program. In exchange, Iran received relief from some of the strong economic sanctions that the United States and others had levied against it. 

The JCPOA allowed for some low-level enrichment of uranium for use as fuel in electricity-producing plants. This was significant, because allowing Iran to operate nuclear reactors for energy actually made it more transparent to inspection. Reports from American monitors confirmed that they had complete access to the Iranian nuclear infrastructure—including careful audits of the nuclear fuel coming and going from the plants— and that the enrichment program had been frozen.

In 2018, Trump pulled the United States out of the agreement, offering no explanation other than that it was a "bad deal"—which is to say, one negotiated by President Obama, whom he loathes. He also reimposed sanctions.

That move left Iran with the ability to begin enriching uranium again at will. Until recently, it was not clear whether it had, but a recent IAEA reports strongly suggests that Iran's stockpile of enriched uranium is approaching what would be necessary to begin assembling nuclear weapons—perhaps in as little as two weeks.

All of this was prologue to two announcements made over the last few days. The first was that on Saturday, Trump's real-estate-lawyer-turned-international-fixer, Steve Witkoff, had made a proposal to the Iranian government for a replacement to the JCPOA. The details suggest that, if anything, Trump's new "deal" would hold Iran to a weaker level of compliance than the JCPOA, and would it allow the enrichment of uranium for fuel.

The second was Trump's claim today that his proposal—contrary to previous reports that the White House didn't contest—would not allow for low-level enrichment of uranium for energy generation. Iran's government had rejected out of hand any proposal without such an allowance, meaning that Trump was essentially declaring the process dead before Iran had even had a chance to consider it—whether or not he knew it.

In other words, this is what appears to have happened: 

• The Trump administration seems to have realized at the last minute that Trump's 2018 destruction of the JCPOA had let Iran come within weeks of becoming a nuclear power. 
  
  
• Trump, or someone acting in his name, proposed to revive the JCPOA, though with concessions to reflect the fact that Iran now has a much stronger hand. 

• Trump's statement's today mean that he either didn't know what he was agreeing to before, or had forgotten it.

This is not the first time in recent weeks Trump has gotten confused about the Iran situation. When he announced his intention to open talks with Iran in April, a reporter asked the obvious question: how would his solution differ from the JCPOA? Trump didn't know what she was referring to, and ducked the question.

Why does this matter?

• Iran getting nuclear weapons is not something a president can afford to be confused about. 

• No matter how good it felt for Trump to undo an Obama administration accomplishment, it's not worth a hostile Middle Eastern dictatorship getting nuclear weapons. 

• This kind of thing is one reason presidents should be able to pay attention to their intelligence briefings even if they're not very entertaining to him.