...Intriguingly, the president broke a little news on the subject of Iran, acknowledging that he personally signed off on the U.S. visit this week by former Iranian President Mohammad Khatami. The trip has angered many conservatives because Mr. Khatami presided over the nuclear weapons development and cheating that Mr. Bush has pledged to stop. Why let him visit?

"I was interested to hear what he had to say," Mr. Bush responds without hesitation. "I'm interested in learning more about the Iranian government, how they think, what people think within the government. My hope is that diplomacy will work in convincing the Iranians to give up their nuclear weapons ambitions. And in order for diplomacy to work, it's important to hear voices other than [current President Mahmoud] Ahmadinejad's."

One thing Mr. Khatami has said this week is that because the U.S. is bogged down in Iraq it will never have the will to stop Iran's nuclear program. Is he right? "Well, he also said it's very important for the [coalition] troops to stay in Iraq so that there is a stable government on the Iranian border," Mr. Bush replies, rather forgivingly.

On other hand, Mr. Bush remains as blunt as ever about the nature of the Iranian regime when I ask if one lesson of North Korea is that Iran must be stopped before it acquires a bomb. "North Korea doesn't teach us that lesson. The current government [in Iran] teaches that lesson," Mr. Bush says. "Their declared policies of destruction and their support for terror makes it clear they should not have a nuclear weapon."

The impression Mr. Bush leaves is of a man deeply engaged on the Iran problem and, like several presidents before him, trying to understand what kind of diplomatic or economic pressure short of military means will change the regime's behavior. One way or another, Iran will be the major dilemma of the rest of his presidency, and Mr. Bush knows it...