Re-reading Vali Nasr’s 2006 book The Shia Revival, I’m struck by how the Saudis were able to fence in Ayatollah Khomeini’s revolution through the late 1980s and early 1990s. Shi’a aspirations and forms of worship often strike pious Sunnis (the majority of Muslims) the way Catholics or Jehovah’s Witnesses appear to strict Baptists, and persecution has been the Shi’a lot for centuries. Ayatollah Khomeini set out to change that, but while he had a massive impact at first, setting up the first properly Islamic state since the peak period of the Ottoman Empire, he was eventually contained by Saudi petrodollars and the growing network of educational institutions they paid for, based on the strict religious principles of the 18th Century preacher Ibn-Wahab. Those Wahabi madrassahs did much to lay the basis for the emergence of the Taliban and related groups.

Khomeini also blundered in backing his allies in Syria against a Sunni uprising (the ruling Assad family are Alawites, who could be compared to Mormons here, in the non-standard nature of their doctrines within Islam), losing any credibility he had with Sunnis. We tend, in the West, to see his main contest as being with the U.S.A. or over his fatwa against Salman Rushdie for writing The Satanic Verses, but at some point or other during the 1980s, he took on half the Muslim world as well as the non-Muslim nations.

The man’s confidence in his own mission still seems stunning. But then, through mystical practices, especially those related to a text called The Four Journeys, he had reached a state where he truly believed he had identified himself with the mind of God. Nasr quotes a story from a disciple, Mehdi Haeri, who had gone to Khomeini to see if there was some way to end the dreadful loss of life happening in the eight-year, Muslim-on-Muslim war with Iraq. Khomeini listened and finally responded, “Do you also criticise God when he sends an earthquake?”

This remark could have been taken in several ways, but Haeri, who had watched the evolution of Khomeini’s mindset over several years, left without responding, and never saw the man again. The idea that Khomeini saw himself, in effect, speaking for God, and his perpetuation of the war was thus beyond reproach, was too much for Haeri.

One of Khomeini’s sharpest critics was Ayatollah Khoei, an Iranian-born cleric who was based in Iraq. He strongly dismissed the notion of a cleric taking on a quasi-Messianic leadership role, and like most other Shi’a ayatollahs, his disciple Ayatollah Ali Sistani, today Iraq’s leading spiritual figure, and the man who helped calm the militancy of Muqtada Al-Sadr’s Mehdi Army, shares that view. Khomeini’s various hints that he might be the Mehdi (or Mahdi), the hidden Twelfth Imam returned to the world, helped build his personal myth after he first took over in Iran. But although he allowed himself to be called “Imam Khomeini,” the term by which Iranians still refer to him, the Mehdi’s actual return would, by definition, be irresistible. Khomeini was a powerful leader, but the war with Iraq was his high-water mark. After that, his revolution was largely contained, except perhaps for Iran’s setting up of the militant Hezbollah organisation in Lebanon.

In the West, intelligent discourse here still doesn’t easily grasp the currents moving through Pakistan or the Persian Gulf states, or see the links to Islamist groups in Indonesia that were influenced by the Saudi countermoves to Khomeini’s revolution. Until I read Nasr’s book, I didn’t grasp that Benazir Bhutto and her father were Shi’a, which explains the militant opposition they faced in Pakistan. Khomeini’s efforts to build Shi’a power and prestige in that country when Shi’a were a minority was a blunder his people are still paying for.

Today, much of what Khomeini strove to do is coming unravelled. His less than charismatic successor Ayatollah Khamenei bungled the elections, insisting it was a religious duty for people to vote, then announcing a result that, while I still think it reflects a plausible, actual outcome, was too obviously fine-tuned. Even by the Islamic republic’s normal accountability standards, it was too much. The subsequent crackdown on those who demanded honesty has done more to undo the notion of a spiritual head of state among its supporters than any number of secular bloggers or activists have accomplished. Khamenei must understand that.

This institution of a Velayat-e-Faqih may persist for years, or even decades. But only someone with Khomeini’s ruthless courage and vision could ever have sustained it, and even he faltered when he had to admit he could not defeat Iraq. Increasingly, it is likely to become an extraneous artifact, an outgrowth from Shi’ism that, like the anguished bloodletting at Ashura festivals to commemorate the martyred Imam Hussein, faintly embarrasses many otherwise devout Shi’a.

That there is no viable alternative in view for Iran is the deeper tragedy. Khomeini’s critics felt that by pulling the religious leadership directly into politics, he ran the risk of diluting popular affection for the faith and its teachers. Khomeini would hear none of this, believing himself to be an unstoppable force. But he died in 1989, and no-one was able to take his place as aspiritual figure.

Worse, as happened in Pakistan, his ambitions were checked. Had he come to power a decade earlier, he might have done more, but the sheer demographics in other Muslim countries were against him. Only in Iraq or little Bahrain are Shi’a numerous enough to predominate. He left his more exposed groups of followers facing a backlash from the strict Wahabi-educated militant groups that are now helping to tear Pakistan apart. That Saudi Arabia itself faces a threat from an Al-Qaeda-style movement, after it was the original sponsor of such things through its thousands of madrassahs, is only one irony of the situation.

My point here is that while there is widespread concern in the West that Iran might be arming itself with nuclear weapons, this has to be seen as an issue related as much to issues on its doorstep as anything itself. Despite the ‘Death to Israel’ rallies, by its physical distance Israel ought not to offer much practical threat to Iran, while Pakistan, which is increasingly gripped by anti-Shi’a movements, is quite likely to pose a major challenge to Khomeini’s entire legacy. I sometimes wonder if the religiously sanctioned practice of Taqiyeh, or dissembling, means Israel is in fact a code-word for Pakistan. Iran and Pakistan share a border, as they both do with Afghanistan. If one of Nasr’s informants (quoted in Chapter Four, Khomeini’s Moment) is to be believed, the Ayatollah once threatened to do to Pakistan’s leadership what he had done to the Shah, and for a time his threat seemed credible.

Presumably western governments understand this perpetually unfolding situation even if mainstream media still tend to talk of Muslims as if they are all radical Sunni fundamentalists. While we are currently watching the helplessness of the Uighurs Muslims in China (who are Sunni), this division between Shi’a and Sunni in the Middle East, in Pakistan and India, and in other countries provides a constant discordant counterpoint to the tide of other events. As Nasr, who is Shi’a himself notes, people of an Al-Qaeda or Taliban mindset see Shi’a as just as undesirable as Americans, Europeans and other intruders into their world. The Shi’a have traditionally kept a low profile to avoid such problems, but for many of them, Khomeini made that impossible by accepting few limits on his ambitions, and thus unleashing the old resentments about perceived Shi’a heresy and apostasy.

Iraq has offered the most visible examples of the bitterness this produces, but it is a factor in all that happens between Beirut and Kabul. And beyond. The execution in Iran this week of Sunni militants for purported terrorist acts is just one indication of this. As the spirit of the Islamic revolution in Iran continues to devolve into political turf wars or worse, it’s worth heeding how these ancient rivalries play out.