operates two systems of cells, one for secure communications and one for propaganda. To send out a propaganda message, Osama must pass it to Kim. If Kim were compromised, the core group might have significant problems with any sort of outside communications. Terrorist networks do not to other cell systems that regularly report to a headquarters. The apparent al-Qaeda methodology, of letting operational cells decide on their final dates and means of attack, exhibits that could easily be used for an indications checklist appropriate for a warning center. Such lists depend on seeing a pattern to give a specific warning. Note that Hassan has two subordinates that have not yet established operational cells. These subordinates can be considered sleepers, but not necessarily with a sleeper cell. Operational cells For each mission, one or more operational cells . If al-Qaeda uses its typical modus operandi of multiple concurrent attacks, there may be an operational cell for each target location. Some operations may need support cells in the operational area. For example, it may be more secure to have a local cell build bombs, which will be delivered by cells coming from outside the area. U.S. special operations forces sometimes wait for presidential authorization to make an attack, or even to move to staging areas. A country would have to face the consequences of an inappropriate attack, so it may tend to be overcautious, whereas a terror network might merely shrug at the world being upset. Assuming that the al-Qaeda operational technique is not to use , their operations may be more also more unpredictable for counterterror forces. If their cells need constant control, there are communications links that might be detected by SIGINT, and if their command can be disrupted, the field units could not function. Since there is fairly little downside for terrorists to attack out of synchronization with other activities, the lack of positive control becomes a strength of their approach to cell organization. Operational cells need to have continuous internal communication; there is a commander, who may be in touch with infrastructure cells or, less likely from a security standpoint, with the core group. Al-Qaeda's approach differs from that of earlier terrorist organizations: Cells are redundant and distributed, making them difficult to 'roll up' Cells are coordinated, not under "command & control"—this autonomy and local control makes them flexible, and enhances security Trust and internally to the cell