Khomeini's Ghost, By Con Coughlin

This is the year of Iran: 30 years on from the Iranian revolution, the eyes of the West are once more on Tehran as Barack Obama promises a new approach in America's dealings with the mullahs if they "unclench their fist". Watershed elections are scheduled for later this year, in which Iranians may turn their backs on the radical president, Mahmoud Ahmadinejad, who has done so much to poison his country's relations with the West.

Khomeini's Ghost, claiming to be the "definitive account of Ayatollah's Islamic revolution and its enduring legacy", is a timely contribution to the understanding of the theocracy that has ruled Iranians for a generation. But Con Coughlin's concern is not with the children of the revolution, for which one must turn to Iran-based writers. His is the eye of the outsider as he delivers a surprisingly dispassionate and workmanlike account of the life and times of Khomeini, without the fire and brimstone that usually characterise his columns in the Daily Telegraph.

But where are the killer revelations that one might expect? Alas, there are none, unlike the insightful BBC series which has just been broadcast. Coughlin reproduces, he claims for the first time, a letter from Khomeini to the Revolutionary Guards' commander at the end of the Iran-Iraq war in 1988, in which the supreme leader "personally referred to the necessity of Iran acquiring nuclear weapons". He also provides a link to the BBC, which broke the story in 2006. But he fails to mention that Khomeini was sarcastically quoting the commander before concluding that "this is nothing but sloganeering".

Coughlin uses this letter as a central theme of his book, saying that Iran's political, military and religious establishment was in some way committed to the success of the nuclear programme. Not least because "in the final year of his life, Khomeini had written about the importance of Iran acquiring nuclear weapons. So far as the standard-bearers of Iran's Islamic revolution were concerned, they were fulfilling Khomeini's dying wish." Iran's modern rulers continue to insist publicly that a religious fatwa prevents them from developing nuclear weapons, something Coughlin neglects to address. The "group think" among Western experts is that Iran is actually keeping its military options open. They believe Iran is continuing to defy UN demands that it halt uranium enrichment in order to be able to "break out" and build a bomb should the need arise.

The recent confirmation by the UN watchdog, the International Atomic Energy Agency, that Iran now has sufficient raw material to turn into enough weapons-grade uranium for a small bomb appears to comfort that position. Nevertheless, Iran continues to maintain that its intentions are purely peaceful. One should not forget that Iran would have to expel the UN weapons inspectors, overcome technical hurdles when under UN sanctions, or go for broke in a clandestine programme if it is to pursue a military route.

The second half of Coughlin's book, which focuses on the post-Khomeini era, is where the author departs from a historical account. Here, he ventures into more controversial territory and highlights more questionable claims, such as the alleged connection between the Revolutionary Guards and Al Qa'ida. But Coughlin is right to dwell on the role of the Revolutionary Guards, whose links to the all-powerful spiritual guide, Ayatollah Ali Khamenei, are crucial. He sought to make them a more effective force to defend the Islamic revolution at home and export it abroad, as he shored up his legitimacy when president of Iran.

As Coughlin points out, the Revolutionary Guards, the shock troops of the revolution, have over the years become a state within a state. Their interests stretch from key sectors of the economy into weapons development and the operation of their own navy, air force and army. Never mind the result of the presidential election next June; the man who wields real power in Iran is Khamenei, and it is he who decides nuclear policy. He is the one to watch during this year of Iran.