Indeed, nothing has been more central to the rhetoric of Osama bin Laden and his followers than denunciations of democracy, legislatures, and "man-made law." The great crime of the rulers of Saudi Arabia, bin Laden declared, is "ruling by laws other than those which Allah has revealed." and thereby making it "incumbent on [their] subjects, by Allah's command, to rebel."

To Iraqis contemplating participation in the January 30 elections, he warned that their constitution was jahiliyya (pre-Islamic) and that Muslims are allowed only to elect a leader for whom "Islam is the only source of the rulings and laws."

The terrorist group Ansar al-Sunnah seconded this notion, telling Iraqis not to vote - and threatening bloodshed if they did - because "democracy is a Greek word meaning the rule of the people...This concept is apostasy." Abu Musab al-Zarqawi, the head of al Qaeda's Iraq affiliate, declared "a fierce war on this evil principle of democracy."

Despite these repeated challenges to Western notions of law and political legitimacy, American policy-makers have shown remarkably little interest in Islamist ideology, and seem content to treat it as simple fanaticism. This is a disabling mistake, comparable to trying to fight Communism without bothering to learn about Marxism. If we are to defeat the jihadists and radical Islam, especially on the battleground of ideas, it is imperative that we better understand their far-reaching ideological ambitions.

Islamic "law" is how shari'a is usually rendered, but this definition is not expansive enough. Although shari'a covers matters of crime and judicial procedure, it provides guidelines for a range of other activities as well, from marriage and economics to spiritual and moral issues like prayer, pilgrimage, and ritual cleansing. The original sense of the term is "the path" or "the way," so it is better compared with the traditional Jewish understanding of biblical and rabbinic law than with a Western legal code. To believing Muslims of every variety, criticism of shari'a as such often sounds strange because, much as they might disagree with stoning adulterous women or cutting off the hands of thieves, the word is roughly synonymous with "justice" or "goodness."

There are several different schools of shari'a, all of them efforts to synthesize material from the Qur'an, the sayings of Muhammad (hadith), and accounts of his life into a systematic body of guidance. The most influential approach among Sunnis is the Hanafi school; among the Shiites it is the Jafari school. Historically, however, shari'a has seldom been the sole source of legitimacy in Islamic polities. Muslim governments have freely adopted local and customary law and, in recent centuries, have borrowed also from Western legal codes.

Most Muslims still live in communities governed by their own distinctive combination of Islamic law and local traditions. When given the choice-as in Muslim-majority democracies like Indonesia, Malaysia, Bangladesh, and Turkey-they have consistently rejected extreme versions of shari'a. Algeria's Islamic Salvation Front might have instituted such an extreme version had the army allowed it to win the election there in 1992, but its campaigning downplayed this part of its program. Similar parties in Malaysia, Pakistan, and Nigeria have managed to win elections only at the provincial and state level.

Despite this lack of popular support, however, radical interpretations of Islamic law have spread dramatically during the past quarter-century, thanks in large part to the aggressive tactics of Islamists and their state patrons. Worse, in a growing number of Muslim countries, those who have taken a stand against extreme versions of shari'a have been vilified, imprisoned, beaten, and even killed.

Agitation for extreme versions of shari'a is nothing new in the Islamic world. It has been central to the agendas of Egypt's Muslim Brotherhood and the Deobandi movement in Pakistan and India for some 80 years. Over the past quarter-century, however, the cause has received an unprecedented boost from two rather different sources.

The first of these is Saudi Arabia. The Saudis have long maintained that their own literalist Wahhabi school of shari'a is the only valid one within the Sunni tradition (leaving aside the still more outrageous heresies, as they see it, of Shiite Muslims). Since the early 1980's, the Saudis have spent billions of dollars to build mosques and madrassas (religious schools) in every corner of the Muslim world for propagating their intolerant creed. Though Osama bin Laden has condemned the House of Saud for its supposed infidelity-and himself hopes to displace the royal family-these institutions have trained vast numbers of actual and would-be jihadists.

Even now, in the wake of 9/11 and while facing a serious domestic threat from al Qaeda, the Saudi regime rejects any law or legislation outside its own narrow tradition as an "infidel" accretion to the pristine teachings of Islam. As Crown Prince Abdullah stressed in a statement late last year, the Saudis are willing to consider any number of political and social reforms - just as long as the centrality of Islamic law is not open to debate. In Saudi Arabia, as in regimes and movements influenced by its example, questioning the government can be regarded as tantamount to questioning God; political opposition can be seen as apostasy or blasphemy, and punishable as such.

Another main source for the spread of an extremist version of shari'a has been Iran, where the Ayatollah Khomeini introduced an unprecedented form of Islamic rule after overthrowing the shah in 1979. By contrast with traditional Shiite practice, wherein spiritual leaders have taken a "prophetic" role in challenging public authorities, Khomeini declared himself head of the government and claimed almost divine powers; his own words, regardless of their relation to sacred texts, would define the boundaries of Islam.

The Iranian fundamental law issued in Khomeini's name bars from political office non-Muslims or Muslims who do not demonstrate allegiance to the mullah's rule, which is referred to as the "guardian-ship of the jurist." The law allows political participation - the formation of parties, rights of assembly, a free press - but only on condition of its "compatibility with standards of shari'a," a restriction that has allowed the authorities to suppress almost every meaningful expression of democratic opposition.

The penal side of Iranian law is equally harsh. For an unmarried perpetrator, the punishment for adultery is 100 lashes; for a married one, death by stoning. It is a crime to listen to certain forms of music or to watch certain movies, and employment is restricted to those who believe in the "guardianship of the jurist." The penalty for killing a woman or a non-Muslim is less than that for killing a Muslim man, and there is no penalty at all for killing "apostates" or members of unrecognized religious minorities like the Bahais.

Despite their strong mutual animosity, Wahhabism and Khomeinism have exerted a revolutionary influence on the Muslim world over the past generation. In country after country, and often in the face of long-standing traditions of moderation, these imported ideologies have provided support and encouragement to local extremists, giving rise to an enormously destructive view of Islam's demands.

The effects of this process may be seen in a brief survey of the landscape.

Pakistan was established in 1947 as a Muslim-majority state but not as an Islamic one. As the independence leader Muhammad Ali Jinnah emphasized, "You may belong to any religion or caste or creed - that has nothing to do with the business of the state." Indeed, the first temporary president of Pakistan's constituent assembly was a Hindu "untouchable."

By 1973, however, a new constitution had been established, renaming the country the Islamic Republic of Pakistan and declaring Islam the state religion. All existing laws, it was declared, "shall be brought in conformity with the injunctions of Islam as laid down in the holy Qu'ran and Sunnah." Though Prime Minister Zulfiqar Ali Bhutto's plans to implement shari'a were stopped in 1977 when General Zia Ul-Haq overthrew him, Zia himself introduced ordinances based on hudud (Islamic criminal law) two years later, including punishments like amputation and stoning. In the 1980's, blasphemy laws were introduced, subjecting those who "defiled" the name of the prophet to the death penalty...

Under Pakistan's influence (and with considerable support from Saudi Arabia), the Taliban regime in Afghanistan began in 1994 to institute its own uncompromising version of shari'a. No formal legislation was involved. Instead, judges or others claiming Taliban authority simply enforced what they believed Islam to require. Women were forbidden to go to school, work outside the home, or travel without a male relative. Apostates and homosexuals were killed, and music was banned.

Even now, under Afghanistan's American-supported democratic government, many of these measures remain in place. The current head of the supreme court, Fazul Hadi Shinwari, has declared that, under his jurisdiction, adulterers will be stoned, thieves will have their hands amputated, and those in possession of alcohol will receive 80 lashes. A non-Muslim, as he told National Public Radio, should be invited to accept Islam; if he does not convert, he must obey Islam; if he refuses such accommodations, the only option, Shinwari said, is to "behead him.".

In Sudan, the long-time ruler General Jafaar al-Numeiri introduced radical shari'a in 1983, partly to win the support of the Islamic Charter Front, an offshoot of Egypt's Muslim Brotherhood... In just the first year of the new laws, 58 public amputations were carried out in Khartoum province alone, including twelve "cross-limb" procedures in which a hand and a foot were cut from opposite sides of the offender's body. Public floggings were broadcast daily on national television, and public hangings, followed by crucifixion, were carried out at sites build especially for the purpose. In 1985, seventy-six-year-old Mahmoud Mohamed Taha, perhaps the country's leading religious scholar, was hanged, having been convicted of apostasy for criticizing the new laws. Opposition to these barbaric practices-which were inflicted for the most part on poor Christians from southern Sudan-renewed a rebellion that, until the recent peace agreement, claimed more than two million lives.

In Nigeria, shari'a personal-status law has been a part of the legal system for decades, but in 1999 Alhaji Ahmed Sani, the governor of the state of Zamfara in the northwest, announced that he would institute a more comprehensive system of shari'a and assign responsibility for enforcement to the hizbah (religious police). Eleven other northern and central states quickly followed suit, closing churches and non-Muslim schools and mandating "Islamic" dress. In 2002, Sani took the additional step of requiring all residents of Zamfara to use Arabic, a language few speak. In the last five years, tens of thousands of people have died in shari'a-related violence in Nigeria. The governor of Yobe state has said that he will defend the new laws even at the cost of civil war, and Sani has urged the advocates of shari'a to form their own armies to defend Muslims and promote Islam.

Militant versions of shari'a have also made inroads in the more moderate corners of the Islamic world. In Malaysia, the Parti Islam SeMalaysia (PAS) came into power in the northern state of Kelantan in 1990, promptly prohibiting the sale of alcohol to Muslims and banning gambling, discotheques, and unisex hair salons. Three years later, the state introduced a shari'a-based criminal code, though it was quickly overturned by the central government. More recently, PAS has experienced several electoral setbacks at the state level, but it remains the only viable opposition in the national legislature and, should the current secular coalition stumble, would stand a chance of forming a government.

Indonesia, too, has experienced only mixed success in resisting Islamist influence. Lawmakers have roundly defeated efforts to incorporate shari'a into the constitution, and the terrorist group Jemaah Islamiah, which carried out the October 2002 bombing in Bali and other attacks, has largely been discredited. But Islamic radicals have managed to advance their agenda through intimidation and piecemeal legislation, especially at the local level. In Sulawesi, Sumatra, eastern Java, Banten, Flores, Sumba, and the Vandung area, they have forced women to wear hijabs, attacked nightclubs, and forcibly closed shops at prayer times. Though lacking in enforcement authority, southern Sulawesi has even enacted Islamic criminal laws.

Indeed, almost everywhere one looks in the Muslim world, Islamists have grown more assertive and violent in advancing their program. In Kenya, the chairman of the country's council of imams and preachers has warned that unless their demands for shari'a-based laws are met, Muslims in the north-eastern provinces will break away. In Tanzania, Islamic radicals have bombed bars and attacked women whom they consider immodestly dressed. Chechnyan rebels have adopted shari'a law from Sudan. The draft Palestinian constitution, in a bow to Hamas and Islamic jihad, declares that the "principles of the Islamic shari'a are a main source for legislation." And so on.

Western attention to the widening influence of extreme versions of shari'a has been, at best, intermittent. News coverage has tended to focus on sensational cases involving the status of women or the imposition of inhuman punishments, as when provincial courts in Nigeria have sentenced women guilty of adultery to death by stoning. Such publicity is vital - it has saved the lives of a number of victimized women - but its effect has been to make shari'a seem a less formidable threat, an unfortunate recrudescence of medieval penology rather than a comprehensive ideological challenge.

As applied to an increasing number of countries, however, extreme shari'a does far more than mete out cruel punishments. With its untrained judges, vague and haphazard standards, nonjudicial decrees, and extrajudicial enforcement, it undermines all efforts at establishing the rule of law. By treating women and non-Muslims as second-class citizens or nonpersons, it systematically deprives Islamic societies of the full benefit of their human resources. Worst of all, perhaps, by turning political dissent and debate into crimes against God, the shari'a of the Islamists closes off any possibility of genuine democratic and religious reform.

Extreme versions of shari'a may thus be the most serious obstacle to the political and religious reform in Muslim societies - and Arab ones in particular - that is needed if democracy is to be established and they are to stop serving as incubators for martyrdom-minded jihadists. For the security of the West, to say nothing of the cause of human rights, reversing the legal and social advances of the Islamists is every bit as important as defeating their armies on the field of battle.

(Paul Marshall is a senior fellow at Freedom House's Center for Religious Freedom)