If you're of a certain age, you may recall newslines like this: "such and such was attacked/bombed/assasinated by a previously unknown group known as [insert name here]." Then, you never heard from the group again.
And if you did, they were called an offshoot, or, for purposes of respectability, an "armed wing."
In Najaf, we recently witnessed something of the same.
A Bimbo Eruption.
Likely to see more.