There is a growing conviction among members of the United States military, and in the international community, that President Bush’s ultimate goal in the nuclear confrontation with Iran is regime change. Iran’s President, Mahmoud Ahmadinejad, has challenged the reality of the Holocaust and said that Israel must be “wiped off the map.” Bush and others in the White House view him as a potential Adolf Hitler, a former senior intelligence official said. “That’s the name they’re using. They say, ‘Will Iran get a strategic weapon and threaten another world war?’ ”

A government consultant with close ties to the civilian leadership in the Pentagon said that Bush was “absolutely convinced that Iran is going to get the bomb” if it is not stopped. He said that the President believes that he must do “what no Democrat or Republican, if elected in the future, would have the courage to do,” and “that saving Iran is going to be his legacy.”

One former defense official, who still deals with sensitive issues for the Bush Administration, told me that the military planning was premised on a belief that “a sustained bombing campaign in Iran will humiliate the religious leadership and lead the public to rise up and overthrow the government.” He added, “I was shocked when I heard it, and asked myself, ‘What are they smoking?’ ”

The lack of reliable intelligence leaves military planners, given the goal of totally destroying the sites, little choice but to consider the use of tactical nuclear weapons. “Every other option, in the view of the nuclear weaponeers, would leave a gap,” the former senior intelligence official said. “ ‘Decisive’ is the key word of the Air Force’s planning. It’s a tough decision. But we made it in Japan.”

He went on, “Nuclear planners go through extensive training and learn the technical details of damage and fallout—we’re talking about mushroom clouds, radiation, mass casualties, and contamination over years. This is not an underground nuclear test, where all you see is the earth raised a little bit. These politicians don’t have a clue, and whenever anybody tries to get it out”—remove the nuclear option—“they’re shouted down.”

The attention given to the nuclear option has created serious misgivings inside the offices of the Joint Chiefs of Staff, he added, and some officers have talked about resigning. Late this winter, the Joint Chiefs of Staff sought to remove the nuclear option from the evolving war plans for Iran—without success, the former intelligence official said. “The White House said, ‘Why are you challenging this? The option came from you.’ ”