In the 20th century, communists waged a struggle for global dominance, but there were conflicts within their ranks as well -- disputes over strategy, ideology and doctrine. Bolsheviks fought Mensheviks, Stalin quarreled with Trotsky (Stalin had the last word: an ice pick delivered to Trotsky's skull), Maoists broke with the Kremlin.

Nowadays, a new global struggle by a new breed of totalitarians aims not at establishing an international dictatorship of the proletariat, but rather Dar al-Islam, a world ruled by Muslims. Among these self-described jihadis there also are disputes over strategy, ideology and doctrine.

Sayyid Imam al-Sharif -- also known by the nom de guerre Dr. Fadl -- may be the most influential Islamist you've never heard of. The Telegraph, a British newspaper, notes that he was "part of the tight circle which founded al-Qaeda in 1988 in the closing stages of the war against the Soviet occupation of Afghanistan." He went on to lead an insurgency against Egypt which landed him in Tora prison in southern Cairo where he has since spent his days thinking and writing.

In 2007, he published The Document of Right Guidance for Jihad Activity in Egypt and the World. In an in-depth report, Daniel Lav, of the invaluable Middle East Media Research Institute (MEMRI), boils Dr. Fadl's "guidance" down to this: The jihadist movement has "strayed from the proper practice of jihad as laid down in Islamic law."

That brought a furious response from Ayman al-Zawahiri, who was once Dr. Fadl's disciple and is now Osama bin laden's top deputy. He wrote A Treatise Exonerating the Nation of the Pen and the Sword from the Blemish of the Accusation of Weakness and Fatigue which alleges that Dr. Fadl was forced to criticize al-Qaeda by CIA and Jewish torturers. Al-Zawahiri also disputes Dr. Fadl's contention that the jihadi movement is militarily and financially unprepared to wage a successful war against the West.

Now Dr. Fadl has returned fire with a new book: Exposing the Exoneration. In it, he comes to a conclusion that would not make him popular at Hollywood parties. "Every drop of blood that was shed or is being shed in Afghanistan and Iraq is the responsibility of bin Laden and Zawahiri and their followers," he writes. "Was it not al-Qaeda that lit the fuse of sectarian civil war in Iraq, through [the actions of al-Qaeda in Iraq commander] Abu Mus'ab al-Zarqawi, who killed the Shi'ites en masse? ...Can the mentality that caused the loss of an Islamic state that existed in reality, in the Taliban's Afghanistan -- can this mentality be expected to establish an Islamic state in Iraq -- in reality, and not on the internet? And have the Islamic peoples become guinea pigs upon whom bin Laden and al-Zawahiri try out their pastime and sport of killing en masse?"

Dr. Fadl also finds fault with the attacks of 9/11/01. "Ramming America has become the shortest road to fame and leadership among the Arabs and Muslims," he observes. [T]o cross the ocean to go to your enemy in its own home and destroy one of its buildings, and [in retaliation] it destroys the Taliban state -- and then you claim to be a mujahid -- only an idiot would do such a thing." "

Perhaps more surprisingly, Dr..Fadl demonstrates that he is not an ends-justifies-the-means kind of guy. He believes that Islamic rules apply even to those who would be Islamic rulers. For example, he criticizes Muslims who settle in the West and then take up arms against their hosts. "If they gave you permission to enter their homes and live with them, and if they gave you security for yourself and your money, and if they gave you the opportunity to work or study, or they granted you political asylum," he writes, then it is "not honorable" to "betray them, through killing and destruction".

Lav notes that Dr. Fadl challenges al-Zawahiri to a kind of Islamic duel -- "a ritual exchange of curses (mubahala), in which each side invites Allah's curse on the party that is lying." Dr. Fadl then adds insult to injury: "Some people pay money for fame, or to promote themselves or their product, but al-Zawahari pays in the blood and lives of his brothers, and leads them to waste away in prison, for his own media fame."

Al-Qaeda's interpretation of Sharia law is not just incorrect, according to Dr. Fadl -- it is a "criminal school of belief." For example, he argues that Islamic jurisprudence does not provide unrestricted permission to use human shields or to indulge in indiscriminate killing of non-combatants. "The number of Muslims whose death and dispossession al-Qaeda has caused in a number of years, in Kenya, Afghanistan, Iraq, Saudi Arabia, Algeria, Pakistan, and elsewhere, is far greater than the number killed or dispossessed by Israel in Palestine and neighboring countries in 60 years," he writes. "So all the talk of al-Qaeda defending Muslims is a tall tale."

Slamming al-Qaeda's leaders for accusing any Muslim who criticizes them of serving the "Crusaders and Zionists" (that is, Christians and Jews), Dr. Fadl goes so far as to imply that al-Qaeda's leaders are themselves apostates for claiming authority that belongs to God alone: "Allah, may He be praised, says that the Muslims' misfortunes are because of themselves, and bin Laden and al-Zawahiri say they are because of America. Let the Muslims consider who they are going to follow: Allah, or bin Laden and al-Zawahiri?"

Finally, Dr. Fadl provides what may be a key insight into how we should fight this war. He says that whenever infidels defeat Muslims, there can be only one explanation: Allah has allowed that as a punishment for the Muslims' sins. Worth remembering the next time someone tells you that winning battles gets us nowhere, that it only makes martyrs of the militants.