THE BURNED OVER DISTRICT

Having established the penultimate brand name in violent, murderous terrorism, followed by determined attacks on its leadership and infrastructure, al-Qaeda is discovering the difficulties of retaining control of your brand.

THE letter bore the corporate tone of a C.E.O. resolving a turf dispute between two middle managers. In formal prose and numbered lists, Ayman al-Zawahri, the leader of Al Qaeda, directed one of the group’s affiliates in Syria to withdraw to Iraq and leave operations in Syria to someone else.

The response was unequivocal. Abu Bakr al-Baghdadi, the leader of the Islamic State in Iraq and Syria, or ISIS, declared that his fighters would remain in Syria “as long as we have a vein that pumps and an eye that blinks.”

It was the first time in the history of the world’s most notorious terrorist organization that one of the affiliates had publicly broken with the international leadership, and the news sent shock waves through the online forums where jihadists meet. In no uncertain terms, ISIS had gone rogue.

That split, in June, was a watershed moment in the vast decentralization of Al Qaeda and its ideology since 9/11. As the power of the central leadership created by Osama bin Laden has declined, the vanguard of violent jihad has been taken up by an array of groups in a dozen countries across Africa and the Middle East, attacking Western interests in Algeria and Libya, training bombers in Yemen, seizing territory in Syria and Iraq, and gunning down shoppers in Kenya.

What links these groups, experts say, is no longer a centralized organization but a loose ideology that any group can appropriate and apply as it sees fit while gaining the mystique of a recognized brand name. In short, Al Qaeda today is less a corporation than a vision driving a diverse spread of militant groups.

“Al Qaeda is kind of a ready-made kit now,” said William McCants, a scholar of militant Islam at the Brookings Institution. “It is a portable ideology that is entirely fleshed out, with its own symbols and ways of mobilizing people and money to the cause. In many ways, you don’t have to join the actual organization anymore to get those benefits.”

Dilution of brand, dissipation of effort and lack of direction. Add to this the inability to even collect franchise fees and we are seeing a major sea change in freebooting murder and violence. When every Tom Dick and Hussein can use you name with impunity, your cause is lost.