spocks brain.... who has spock's brain?
"But who is the genie's brain?"
Curiously, he may not have one. Not in the singular. Militant Islam is a world view, imbued with many regional cultural characteristics, which arises from a mindset which has become second nature to its practicioners. This phenomenon has been observed among lifelong Communists, leading one person to characterize the international left as "the Hive". If you are scripturally inclined, you might take this answer:
"He asked him, "What is your name?" He said to him, "My name is Legion, for we are many"