The leaders of Iran, the ayatollahs, keep threatening that Israel, the Little Satan, and its master, the Great Satan - America - will be vanquished before long (three to five years?) by a triumphalist, nuclear-armed Islam determined to establish Allah's rule even at the cost of martyrdom. Yet the world does not seem too exercised. In fact Russia and China lend Iran a helping hand. How serious is this threat, and, if it is serious, how to face it? At least part of the answer to these questions may involve factors, religious, nationalist and economic, that are not commonly discussed. Living in a secular culture, most of us underestimate the determination of true believers. We forget that only recently a relatively civilized Europe was engaged for centuries in the most bloody religious - and then ideological - wars. So we do not fully appreciate how martyrdom-seeking fanatics may take extraordinary risks and ignore the restraints that a balance of terror imposed on atomic confrontations in the past. ESTABLISHING Muhammad's law by the sword, a basic duty for many Islamists (the Islamic empire stretching from ocean to ocean was not won, remember, by turning the other cheek), demands that Shi'ite Iran not only vanquish the Dar El-Harb (House of War) of Christendom, but also the intolerable Sunni heresy. The ayatollahs are therefore cleverly leveraging their war against Christianity and Judaism to also undermine, and eventually vanquish, Sunni regimes. For Jihadist Shi'ites, Sunni control of the holy cities of Mecca and Medina, by their most extreme sect, the Wahhabists, must be as outrageous as was the Muslim conquest of Jerusalem to the Crusaders. They must fervently feel that Saudi occupation has to be destroyed and replaced by Shi'ite rule. But there are other, national and economic, reasons why the ayatollahs seek the destruction of Saudi Arabia, an ally of The Great Satan. A proud and racist (Aryan) nation, the Iranians have probably not forgotten nor forgiven Saudi support - and perhaps instigation - of Saddam Hussein's bloody war against them. It took decades, but the Iranians avenged America for deposing Muhammad Mossadeq's nationalist government. They killed hundreds of marines, kidnapped, tortured and brutally executed CIA operatives; they took American diplomats hostage and humiliated them. They will do the same, and worse, to the Saudis when they get a chance. AS FOR economics: After having destroyed its prosperous agricultural sector by slapping on price controls that benefited its lower-middle-class supporters (the Bazareens), the ayatollahs have had to spend an annual fortune on the huge welfare system that supports millions of farmers who migrated to city shanty-towns. Welfare, allocated by family size, encouraged a population explosion that more than doubled Iran's population and created a huge burden on the national treasury. The Iranians, who always pushed for higher oil prices even under the Shah, are now dependent for their survival on high income from oil. Saudi Arabia wants to curb oil prices to avoid development of alternative fuels and sources. Control of oil prices is behind Iran's systematic military preparations to control the gulf's shipping lanes. It was behind the bloody Iraq-Iran war, and it is still a major Iranian objective. It made Iran occupy the islands in the gulf's exit and establish a base in the horn of Africa to stop US reinforcements coming through Suez. The possession of an atomic bomb will, at a minimum, neutralize Western resistance to Iran's gradual control of the flow and price of oil. Iran could counter any Western intention to intervene militarily against such control by a credible threat to blockade oil shipping or incinerate the gulf's oil fields and vulnerable loading facilities, thus plunging the West into a deadly economic crisis. The West is not likely to confront a fanatic, nuclear-armed Iran over the price of oil. It will most likely compromise, namely, cave in. Iran will then be able to initiate a huge transfer of wealth that will gradually impoverish and strangulate Western economies and facilitate their "peaceful" domination by Islam (see what Arab oil money has already achieved in Europe). If an opportunity arises then to demonstrate their determination and supremacy, the ayatollahs will no doubt try to annihilate Israel. MEANWHILE, the Iranians cleverly exploit Arab, especially Saudi, hatred against the West and Israel, not only to distract attention from their ultimate goals but to actually assist them, as in Iraq, to gather jihad under the Shi'ite flag. Their sponsorship of worldwide terrorism, their undermining of any possible settlement of the Palestinian issue helps them rile up and distract Arab Sunni masses. They hope that, eventually, when the tsunami of Muslim anger finally breaks its bounds, as they predict, it will also sweep away corrupt Sunni Arab regimes and replace them and their by-then discredited dispensation, by a purer and triumphant Shi'ism. This is an argument I made as long ago as the early 1990s (in The Wall Street Journal, The Financial Times and The Jerusalem Post). A strict oil blockade then, resulting in a severe cut in income, could have undermined the stability of the ayatollahs' regime, dependent on huge welfare payments. It would also have denied them the means for their costly atomic program. Today it may be too late. However, it may still be worthwhile to test how the ayatollahs' welfare- and military-dependent regime copes with a severe drop in oil income. Otherwise, military action seems the only alternative.