He was remarkably relaxed and chatty, as though it were just another Monday.

But in a midday appearance in the East Room on March 2, President Donald Trump was delivering the first public explanation of the extraordinary U.S. and Israeli assault on Iran that has upended the region and may well define his presidency.

More: US strikes Iran: Trump’s gamble could spark wider Iran war

He outlined his goals, notably not mentioning the regime change he had encouraged over the weekend. He promised success but didn't outline a firm timetable.

"Whatever the time is, it's OK, whatever it takes," he said, saying they were running "substantially" ahead of the original projection of a campaign that would last four or five weeks. He insisted he had the backing of the world. "Everybody was behind us, they just didn't have the courage to say so."