What is considered the first line of defense against unlawful entry of aliens and contraband into the U.S.?

The choice of Linewatch Operations as the first line of defense against unlawful entry of aliens and contraband into the U.S. is justified by the specific role that this tactic plays in border security. Linewatch Operations involve the continuous monitoring of the border areas, primarily along remote and less-patrolled regions. This proactive approach enables agents to detect and prevent illegal crossings before they occur, thus acting as a crucial barrier against unlawful entry.

Linewatch Operations are strategically positioned to cover areas where electronic surveillance might be limited, making it essential for agents to physically patrol and observe potential crossing points. This method allows for rapid response to any violations, underscoring its importance in maintaining security along the border.

In contrast, checkpoints serve as fixed points to assess vehicles and individuals passing through but can only monitor traffic at those specific locations. Mobile patrols, while valuable, focus more on transportation corridors or areas adjacent to the border rather than directly monitoring the border itself. Surveillance Operations rely on technology such as cameras and sensors, which enhance detection capabilities but cannot provide the immediate, on-the-ground response that Linewatch Operations facilitate. Therefore, Linewatch Operations are most effective in immediately addressing the threats posed by unlawful entry, solidifying their position as the first line of defense.