What is the outermost defensive zone called in the three-layer zone of defense?

The outermost defensive zone in the three-layer zone of defense is known as the assessment zone. This zone serves as the first line of detection and evaluation for potential threats. It is primarily focused on identifying possible risks before they reach closer, more defined areas of security. In this zone, personnel monitor and assess situations, gathering information to determine whether a real threat is present. This proactive approach allows security forces to react appropriately and effectively.

Among the other zones mentioned, the threat zone typically refers to areas where an immediate threat is present, the warning zone signifies areas where alerts or heightened awareness are necessary, and the secure zone is where controlled access is imposed post-assessment. Understanding the unique roles of these zones is crucial for effective security operations, making the assessment zone vital in establishing a proactive defense strategy.