Reza Aslan has written, first and foremost, a great introduction to Islam,
particularly to its early history. The first chapters show how Islam emerged
from the tribal society of the Arabian peninsula. Then he briefly describes
how the Islamic empire fell into the hands of caliphs who had little interest
in theology, while the ulama developed the theology.
Then Aslan leaves the political history of the Islamic world to focus on what happened to the Quran. The ulama set out to interpret the Quran and to derive a set of laws based on the "hadits" (the acts and words of Mohammed). Aslan points out that a) the "hadith" (and therefore the shariha that followed) were work of humans not divine revelation, and b) the Quran itself must be interpreted in its historical context (in fact it contradicts itself, as Mohammed said different things in different contexts). Given these two facts, any "Islamic law" is an oxymoron. There is an absolute faith in Allah, but there is no divinely prescribed behavior: the prescribed behavior was decided by a group of people who were not prophets (they did not have divine revelations). Using Islam's own principles, Aslan shows that most of today's Islam is founded on a misconception.
Aslan has therefore also written another book, a book that sets to prove how the current turmoil in the Islamic world is not the product of a war against the rest of the world but an internal civil war between traditionalists and reformists. He sees it as the equivalent of the European Reformation. Aslan thinks that in the past the Islamic masses had to rely on the few knowledgeable scholars for the interpretation of the Quran, whereas the increase in education of the 20th century is eroding that monopoly and allowing more and more interpretations to emerge. Aslan thinks that the fundamentalists attack the West as a way to galvanize the Islamic world. Every victory (such as the successful attacks of September 11 or the withdrawal of Israel from Gaza) is interpreted as confirmation that one specific interpretation of the Quran (the fundamentalist one) is correct. In other words, Aslan thinks that the fundamentalists don't necessarily want to impose Islam on the entire world: their goal right now is simply to restore what they view as the purity of Islam on the Islamic world itself.
It's a far-fetched thesis, that probably overestimates the intelligence of the fundamentalists. When they kill women in the streets of Baghdad or stone them in the stadium of Kabul, it is obvious that their aim is the Islamic society itself. When they spend years planning an attack against a Western city, it is much harder to believe that their aim is the Islamic society and not the non-Islamic world.
After all, their interpretation of Islam is that Islam is a mandate from Allah to convert the whole world, one way or another. The problem is that their interpretation of Islam is precisely the interpretation of the people who knew Mohammed. Otherwise we would not have the problem in the first place: it was the early followers of Mohammed who invaded the lands from Spain to Indonesia. They did not content themselves with "purifying" their Arabian society: they invested all their resources on invading the whole world. They stopped only when they were defeated by more powerful armies.
Aslan himself is an example of the conflict within Islam. In numerous detours, he spends a lot of time trying to dispel notions that Islam is a militant religion, that Mohammed never meant to launch a violent jihad against anyone, that Islam never meant to invade, kill, destroy. In other words, he spends quite a bit of time trying to prove that Islam is about peace, not war. The non-Islamic world would love to see Aslan's theory of Islam adopted by all Muslims of the world.
Unfortunately, most Muslims of the world have read the Quran more carefully than Aslan and remember the verses "Slay the polytheists wherever you find them", "Find those who do not believe in Allah", etc. According to Islam, those verses come from Allah. They know that Mohammed raided caravans for the sole purpose of robbing them: they were infidels, and therefore violence against them was justified. Aslan tries to find a justification in the ancient tribal logic for Mohammed's robberies, but, at the end of the day, a bandit is a bandit is a bandit. Jesus did not rob people, Buddha did not. Mohammed did. Aslan tries to minimize Mohammed's massacre of Jews at Banu Qurayza (Aslan points out that the Jews killed by Mohammed were only a fraction of all the Jews in Medina, as if this made it acceptable). How many massacres did Jesus carry out? How many did Buddha? How many by any other founder of a religion anywhere in the world? Aslan points out that "only six men and four women were put to death" when Mohammed conquered Mecca. Only? How many people were put to death by Jesus? Only someone who has been brainwashed as a child to be a Muslim can live in such denial of the truth. Aslan is like the orthodox Catholic historian trying to justify all the actions by the Popes. Aslan's misunderstanding of the values of the non-Islamic world peaks when he hails Mohammed's destruction of the idols at Mecca. What eludes Aslan (and one billion Muslims) is that Mecca before Mohammed was a model of religious tolerance. Mecca before Islam was precisely the kind of society that the USA is trying to be: all religions were allowed and coexisted peacefully. Mecca after Mohammed became a model of religious intolerance: only one religion was allowed. And today it is still the same. No wonder that so many Muslims hate the USA so viscerally. The USA stands for what Mecca used to be before Mohammed destroyes the idols. We, basically, want the idols back, and want Mohammed locked in a mental institution for dreaming of a god who wanted him to raid caravans, massacre Jews and overthrow the government.
What Aslan is trying to do is found a new religion, that turns Mohammed's teaching and the Quran's literal sentences upside down. This would be very welcome by the non-Islamic world.
It is not clear what Aslan suggests for the future. He indirectly blames Western interference awkward for weakening (instead of strengthening) the reform movements in the Islamic world. Aslan correctly points out that the USA's opposition to Khomeini unified Iran around Islam and kept the revolution from evolving into a democratic regime. Aslan correctly points out that Al Qaeda was legitimized by the first Gulf War, in which the armies of the infidels were stationed in holy Saudi Arabia and then invaded the Islamic lands of Iraq. But he does not emphasize that, without those events (no matter how clumsy), the ulama would still be running the Islamic world, and there would be no reform movement at all. It is contact between the West and the Islamic world that has prompted some in the Islamic world to ask for reforms. It is contact with other religions that is slowly steering Muslims away from the dogmas of Islam. He is right that Western intervention tends to unify the Islamic world against the West (no matter how horrible the problem that the West tried to rectify), as in 2003 when the entire Islamic world was rooting for a dictator they had always hated (Saddam Hussein). But he does not offer any advice to the West on what to do.
There is another point that Aslan fails to make. Both the Soviet Union and China largely solved the Islamic problem. The method they used is the good old method of extermination. It worked in both countries (the war in Chechnya was a reaffirmation of that policy and, again, it seems to have worked). The two places where the Islamic problem has deteriorated are the West and India that, having developed a sense of respect for minorities and other cultures, used a different method: try to assimilate the Islamic world into values of democracy.