What did Donald Trump do today?

He forgot his Iran policy.

As of yesterday, the official policy of the Trump administration was one of active support for anti-government protestors in Iran. 

At about 2:30 p.m. London time today, Trump had this exchange with a reporter at the NATO summit.

Q    You mentioned earlier the Iran protests.  Does the United States support these protestors in Iran? 

TRUMP:  I don’t want to comment on that.  But the answer is “no.”  But I don’t want to comment on that.

Less than an hour later, somebody posted this to Trump's Twitter account:

The United States of America supports the brave people of Iran who are protesting for their FREEDOM. We have under the Trump Administration, and always will! 

A few minutes later, Trump—now at a different press availability—claimed he'd misunderstood the question.

The question was asked: “Do we support them” — I thought — “financially?” And we haven’t supported them. I don’t know that we’ve ever been actually asked to support them, financially. And I — you know, if somebody asked, maybe we would. But we support them very, very seriously.

Given the nature of the Iranian protests—not something anyone would think you could write a check to—this latest explanation doesn't make much sense.

Remembering his stance on Iran shouldn't have been difficult for Trump, who has never warmed up to the Iranian government the way he has to other hostile authoritarian regimes, like Russia or North Korea. (Trump also affectionately mentioned Kim Jong-un today, even as North Korea ramps up its threats.)

But Trump often forgets his own stance on signature issues, only to be gently "corrected" by his staff.

How is this a problem?

• It's very bad if the president is forgetting, in real time, what his position is on major conflicts.