December 15 is the outer time limit of a decision window for Tehran and the West. That is the date for the mullahs' "Assembly of Experts" to decide whether to choose  a new Supreme Leader.

The most nuke—happy candidate for the top job is  Ayatollah Yazdi, Ahmadinejad's personal guru. If Yazdi becomes Supreme Leader, with Ahmadinejad as President and his Islamic Revolutionary Guards now purging the universities and ministries, the most dangerous faction will monopolize all positions of power in Iran.  These are people who thirst for martyrdom. Give the radicals their own nukes, and all bets are off.

Can the rational world influence the regime? Oddly enough, it may be Israel that has the necessary carrot and stick. Europe is a fake power; nobody takes it seriously.  The mere existence of a vast US nuclear array does not intimidate Ahmadinejad, because the US is not directly threatened. He also knows that conventional US strikes are time—limited by domestic political pressure. It is only Israel that can change the strategic equation quickly and possibly shock the mullahs out of their mad fantasy game.

The pragmatists in Tehran are survivors. They don't want to repeat the horrific Iran—Iraq war. People like Rafsanjani didn't become superwealthy by risking their necks. In contrast, the radicals think of themselves as martyrs—in—waiting, ready for Allah's Paradise. Ahmadinejad parades his willingness to have another Khomeini—style wave of glorified suffering; the last time, that cost Iran hundreds of thousands of lives.

Ahmadinejad may be making a show of his thirst for martyrdom to frighten the West.  But it is also who he really is. His personal history during the Khomeini years is entwined with a quest for martyrdom. It is therefore important to convince the pragmatists that the Ahmadinejad faction is leading them to certain doom. Such a demonstration should happen sooner rather than later.  By December 15 it may be too late.

Israel has a stick it can safely wield ——— an underground nuclear test explosion. Israel's technology is years ahead of Tehran's, but that fact does no good at all unless it is dramatized in a way that all Iranian factions must explain to their constituents. Ahmadinejad has been poo—pooing Western power, but a test explosion under the Negev Desert will demonstrate to all sane observers that Israel is not a paper tiger.

Reportedly, Tehran came away from the Lebanon War with the impression that Israel can be easily knocked over. That is what  Ahmadinejad keeps telling his domestic audiences. His followers are ready to believe it. A test explosion will make it clear to them that he is bluffing, and putting their lives on the line to boot. That may not appeal to them.

It is the Shiite poor who were the cannon fodder for the Khomeini regime in the Iran—Iraq war. These people are routinely suckered by the regime's propaganda, but an Israeli explosion is one thing that can't be hidden from them. They are human beings, and they have plenty to fear from their mad leadership.

A nuclear test is a big stick. Israel also has a carrot:  a vigorous peace initiative. Europe is willing to take a North Korean nuclear test in its stride because it still thinks that's somebody else's problem. But Europe will explode in rage after an Israeli bomb test. The French, Brits and Germans have been primed by years of propaganda to think the worst of Israel and the United States. Now they also have knife—wielding  Muslims living next door in every major city, which scares them even more. Any test must therefore be accompanied by a credible peace initiative, which promises to make the world genuinely safer.

An Israeli peace proposal will mobilize the reflexive pacifism of European public opinion. Israel could propose intrusive nuclear—facilities inspections throughout the Middle East. That would put the onus on Tehran to respond in a serious way,  and mobilize great pressure from Arab nations that have no desire for a nuclear Persian Caliphate next door. If Tehran fails to respond, its extremely risky course will be dramatized for the entire world to see.

Combine the stick with the carrot, and it may be possible to  catch Tehran's attention at a crucial moment, before the Yazdi gang takes power.

What are the downsides of this carrot and stick? Israel's nuclear program would be out in the open. Its weapons test would be cited by Tehran to justify its own nuclear programs. But these objections are no longer significant: first, because everybody knows about Israeli nukes anyway, and next, because Tehran needs no excuse to go hell for leather for its own doomsday weapons. Both of those things are already happening.

The trickiest technical question is how to set up an inspection regime that would assure enemies that they can stay safe if they behave rationally. If there is a way to do it, it may set the standard for a worldwide anti—proliferation regime, perhaps applicable to North Korea and Pakistan. It is worth exploring.

The only sane way to actually use nuclear weapons is to stabilize the perceived balance of forces. That has worked for sixty years among rational opponents, but it would not work for Tojo's Japan, for Hitler in his bunker, and perhaps for the martyrdom cult of Ahmadinejad. It is therefore crucial for the world to demonstrate to the mullahs what will happen if they pursue their present course.  An Israeli test explosion might sober up even Ahmadinejad, if he is rational; and if he is not, his pragmatic competitors will have plenty of reason to get rid of him.  They will only get serious if their own lives are on the line.

James Lewis is a frequent contributor to American Thinker.