Can the violent jihad do without sympathizers?

According to some terrorist fighters and academicians, the constituencies of Muslim extremists are vital to the persistence of the jihad. I have established that although sympathizers are indispensable for recruiting and sponsoring, they are less crucial for making foreign journeys, generating revenues, and communication. This is not only so because sympathizers re-fuse to help because of fear of retaliation, but also because it is unnecessary, impossible, or unfavorable for extremists to recourse to their constituencies. Therefore, sympathizers may be important for the persistence of the jihad, yet their role is not self-evident.