Consider up front the requirements for deadly physical force under civilian law. Suppose you have a gun (a weapon that is on a personal level the national equivalent of nuclear weapons) and someone yells that he is going to kill you. You are not justified in shooting him if he obviously lacks the means to carry out his threat because your life is not in danger. If he has a gun but has not displayed any intention of using it against you-- as would be the case with a hunter, a police officer, or another armed citizen-- you are obviously not justified in shooting either. If, however, he says he is going to kill you AND he displays the means of doing it, you are probably justified in shooting him on the spot.

Now suppose he says he is going to kill you and then begins to assemble a firearm in front of you, as Iran is assembling nuclear weapons. I doubt that many district attorneys would have a problem with your shooting him before he can complete his task, noting that alternatives that might be available in civilian society like retreating to a place of safety and calling the police are not available to countries. (Calling the United Nations is of course useless.) Tel Aviv cannot move to a place where it is immune to an Iranian nuclear attack, nor can New York, London, and Washington DC go somewhere a terrorist cannot detonate an Iranian-supplied suitcase bomb.

Ahmadinejad has said openly that he plans to "wipe Israel off the map" and, in a carefully-orchestrated public-relations event, he has shown a ball with the Star of David falling through an hourglass. Note, however, the identity of the country that is to be destroyed before Israel:

And the above picture is not the mere delusion of a madman but rather a premeditated and well-planned public relations event (http://www.theodoresworld.net/).
This individual may, in fact, be more dangerous than Hitler because Hitler was partly insane and therefore subject to irrational and self-destructive decisions.

The bottom line is that demonstrated intent (shown above) and imminent means justifies a conventional or even a nuclear first strike to prevent Ahmadinejad from carrying out his intent. This is not to say that the U.S., UK, or Israel should use any more force than necessary to destroy Iran's nuclear program and government. Using a nuke where a conventional bomb would do would be "excessive force." Fortunately, American weapons are extremely accurate and can achieve their missions with conventional or low-yield nuclear warheads.

Meanwhile, destroying Iran's government would free tens of millions of people from fear of arbitrary arrest, torture, and execution. It would be a blessing to at least half the population (the female half) which must currently live in terror of being raped, tortured, hanged, and/or stoned to death on a whim. There was, for example, a recent case in which a woman was sentenced to hang for killing a man who was raping her. There is nothing wrong with the judge who issued that sentence that heat sufficient to fuse sand into the mineral known as Hiroshimite, 12 pounds per square inch of blast overpressure, and/or 1000 Roentgens of gamma radiation would not fix.

The other issue consists of Ahmadinejad's long history of messianic demagoguery, a premeditated act of dramaturgy by a man who would be God.

Costumes helped symbolize the power of participants in the ritual over nature. Masks were especially important: the bigger the mask, the greater the power. In fact, the wearer of the mask was more important than a representation of the "god," he was the god; he had the power. Dramaturgy, then, did not begin as entertainment. It began because the human organization, in order to maintain itself, needed some part of a ritual performance to come true.

Klein, Stewart M. and Ritti, R. Richard. 1984. Understanding Organizational Behavior.

John Keegan's The Mask of Command (1987) adds,

The theatrical impulse will be strong in the successful politician, teacher, entrepreneur, athlete, or divine, and will be both expected and reinforced by the audience to which they perform. …What they know of him must be what they hope and require. What they should not know of him must be concealed at all cost.

Long before he became dictator of Iran, Ahmadinejad has been conducting a well-orchestrated campaign to prepare for the coming of the Mahdi or Islamic Messiah. This fits exactly the role of the Antichrist of Revelations, a messianic demagogue who will claim a divine origin or connection to rally hordes of mindless fanatics behind him.

In fact, Mohammed and the first Mahdi, slave trader Mohammed Ahmed, already used these methods with horrific results. Fictional examples of messianic demagoguery include Frank Herbert's Dune, in which Paul Muad'dib's mother uses a Fremen legend to present her son as the Messiah-- only to discover that he IS the genetically-bred Expected One. (The story is, in fact, probably based on the story of Mohammed, noting that the Fremen are essentially Arabs and Paul, like Mohammed, had to flee into the desert to escape enemies.) Another is Kipling's The Man Who Would Be King, in which two adventurers use Masonic legends to set themselves up as rulers of Kafiristan.

Iran's Messianic Menace By Daniel Pipes FrontPageMagazine.com | January 10, 2006 (Click on the link for the complete article).

Thanks to Mahmoud Ahmadinejad, the president of Iran, a new word has entered the political vocabulary: mahdaviat.

Not surprisingly, it's a technical religious term. Mahdaviat derives from mahdi, Arabic for "rightly-guided one," a major figure in Islamic eschatology. He is, explains the Encyclopaedia of Islam, "the restorer of religion and justice who will rule before the end of the world."

When he was still mayor of Tehran in 2004, for example, Ahmadinejad appears to have secretly instructed the city council to build a grand avenue to prepare for the Mahdi. ..When addressing the United Nations in September, Ahmadinejad flummoxed his audience of world political leaders by concluding his address with a prayer for the Mahdi's appearance: "O mighty Lord, I pray to you to hasten the emergence of your last repository, the Promised One, that perfect and pure human being, the one that will fill this world with justice and peace."

On returning to Iran from New York, Ahmadinejad recalled the effect of his U.N. speech:

...one of our group told me that when I started to say "In the name of God the almighty and merciful," he saw a light around me, and I was placed inside this aura. I felt it myself. I felt the atmosphere suddenly change, and for those 27 or 28 minutes, the leaders of the world did not blink. And they were rapt. It seemed as if a hand was holding them there and had opened their eyes to receive the message from the Islamic republic.

If Ahmadinejad says it, his followers are going to back him up unless they want to find themselves hanging from cranes in Tehran or even worse. Ahmadinejad is indeed the man who would be God and he must be stopped NOW.