Which FPCON indicates that a terrorist attack has occurred or is likely?

The correct choice reflects the highest level of security alertness within the Force Protection Condition (FPCON) system. FPCON Delta is utilized when there is a confirmed terrorist attack in the area or when specific intelligence indicates that an attack is imminent. This level necessitates the most stringent security measures and heightened awareness among personnel, as it signifies that immediate action is required to protect lives and resources.

In FPCON Delta, the focus is on direct response to an existing threat, often involving significant security forces and restrictions on movement. The situation demands that all personnel are vigilant and prepared for potential escalations or further attacks.

In contrast, the lower FPCON levels such as Alpha, Bravo, and Charlie indicate varying degrees of threat awareness and preventive measures but do not signal an immediate or confirmed threat. FPCON Alpha denotes a general, low-level threat; FPCON Bravo indicates a more substantial, yet not urgent, threat; and FPCON Charlie suggests a heightened risk of attack but does not confirm that an attack has occurred. Hence, FPCON Delta uniquely designates a state where threats are either confirmed or currently unfolding, requiring the highest operational readiness.