You're at a photo op, reading a book with schoolchildren and an aide suddenly whispers that a second plane has hit the World Trade Center."America is under attack."

You're the president of the United States. What do you do?

There have been other moments like this in American history, when the chief executive was suddenly plunged into a crisis, but they weren't caught on videotape. George W. Bush was on camera in an elementary school in Sarasota, Fla. He could see the pagers of reporters and photographers going off, one by one. He was on the spot like few people have ever been.

From two different angles, Americans have new glimpses of that historic moment. One comes from rabble-rousing Michael Moore, whose Bush-eviscerating film"Fahrenheit 9/11" premieres next week, and includes an uninterrupted seven-minute segment showing Bush's reaction after hearing the news of the attack. He doesn't move.

Instead he continues to sit in the classroom, listening to children read aloud. Moore lets the tape roll as the minutes pass painfully by.

And now from a second angle: The staff of the 9/11 Commission this week released a report that summarizes Bush's closed-door testimony about his thoughts as he sat there.

"The President told us his instinct was to project calm, not to have the country see an excited reaction at a moment of crisis . . . The President felt he should project strength and calm until he could better understand what was happening."

This moment will surely be used by the president's political opponents, and with equal fervor defended by his supporters. However it is interpreted, it points out a basic truth about any president: He's both an executive and a symbolic figure. He's the spiritual leader of the nation as well as the head of state. He's monarch and prime minister.

Sometimes he has to decide what role to take.

Presidential historian Robert Dallek of Boston University thinks Bush focused too much on appearances, rather than leaping into action.

"It speaks volumes about the preoccupation these politicians have about manipulating image," Dallek said yesterday. Bush should have immediately excused himself and started figuring out what was happening and what he could do."The way to project calm and strength is to take care of business."

Douglas Brinkley, a presidential historian at the University of New Orleans, concurs:"I don't understand how one sits there. I just don't. Minutes are an eternity in that sort of situation. . . . A quick presidential decision may save lives." Brinkley credits Bush with dusting himself off after a rough first day and regaining his composure. And he acknowledges that few presidents have had to endure such a Candid Camera moment. But Brinkley adds,"Character is not defined in good times, when you've been properly briefed, it's defined when you're in a desperate crisis situation."

Presidential scholar Fred Greenstein, a professor emeritus at Princeton, defends Bush's response in the initial minutes.

"It's made a little more complex by being in the presence of little kids," Greenstein said."It certainly wouldn't present the right message if he turned white, rushed out, and kids started crying."

The commission report this week is not the first glimpse into Bush's thought processes in the critical minutes after the first planes crashed. Bush has previously told Bob Woodward,"They had declared war on us, and I made up my mind at that moment that we were going to war…."