The problem for the intelligence agencies is that they're now dealing with an enemy that has restructured in response to the setback it has suffered.
It now operates in autonomous cells that can change shape and tactics at will. Finding and neutralising them before they can strike is even more difficult. And the greatest fear is that a suicide bomber, a lone wolf, will emerge.
Exactly. They don't carry an Al Qaeda membership card in their wallets, it is precisely a decentralized collection of misfits and wannabes. There are common characteristics. They tend to be influenced by Wahab ideology. There is often a link to Saudi money. They are occasionally used as cannon fodder by someone else who doesn't want to declare himself. That could be Iran, Iraq, the ISI, some member of the Saudi elite, or he may simply be free-lancing. At that level it is hard to distingish since despite their differences they all agree on the need to isolate the US.
Which is the other characteristic. They are Al Qaeda if their target is the US. We don't use that term if they are attacking Israel, or India, or Russia, although they may be otherwise indistinguishable.
So if you have an attacker who is not directly paid by a state intelligence service, whose money is laundered to him through some kind of Saudi charity, whose target is the US rather than Israel or India or Russia, we label him "Al Qaeda" as a convenience.
Bears repeating. Years...