Weighing in at 364 pages, the Rand Corporation has just released a two-part study, “Beyond Al Qaeda.” Al Qaeda espouses a "global revolutionary creed” with an “ideology that is radical and Islamist at its core, but also borrows from 20th century Western totalitarian traditions.” Its goals, Rand notes, “are to mobilize Muslims for a global jihad against the West; topple ‘apostate’ regimes, particularly in Saudi Arabia, Egypt and Pakistan; and create an Islamic government spanning the Muslim world based on an ultra-orthodox interpretation of Sunni Islam that would isolate the majority of Sunni Muslims as well as Shi'ite Muslims.”

On Iraq, Rand outlines three scenarios:

In the end, terror alone cannot guarantee success for the insurgents. The insurgency can continue to wreak havoc but will become an exercise in political futility. In these circumstances, three general scenarios are possible:

In the most benign case, significant elements of the Sunni community realize that a return of the status quo ante is no longer viable and accept a minority role within a democratic Iraq. The Sunnis might find a common interest with the Kurdish parties in balancing Shi’ite predominance, and a rough balance of power could develop, allowing for what we called in another study “democracy with Iraqi characteristics.”

In the second scenario, the representatives of the Sunni community are too alienated or terrorized to enter into a political arrangement with the Shi’ites and the Kurds. The insurgency could continue, perhaps at high levels of violence, but would be unable to transcend its narrow social base or to prevent the nascent government from gradually consolidating its control over the country.

In the third scenario, if the new government is unable to contain the insurgents and terrorists, or to win broad support among the diverse ethnic and religious communities in Iraq, it will be no match for local warlords and will have to contend with the growth of terrorist infrastructures. A failure of central authority could lead to a formal or de facto partition of the country.

Would an American troop withdrawal, along the lines suggested by many senior Democrats, make the third scenario more or less likely?

Here’s volume one, The Global Jihadist Movement , and volume two, The Outer Rings of the Terrorist Universe .