What is the role of the final coordination line in an assault?

The role of the final coordination line (FCL) in an assault is primarily to coordinate supporting fires and the deployment of assaulting forces. This line is established to ensure that all supporting elements, such as artillery or air support, are synchronized with the main effort of the assault. By designating a specific line for coordination, commanders can effectively manage the timing and placement of fire support, ensuring that it does not interfere with their own forces while they advance toward the objective. This enhances the effectiveness of the attack by minimizing risks to friendly troops and maximizing the impact of supporting fires.

In the context of the other choices, controlling withdrawal of forces typically refers to a different operational phase and set of procedures. Establishing a defense perimeter is more related to securing an area after an offensive operation rather than during the assault itself. Defining limits of engagement does play a role in engagement rules but is more focused on engagement with potential enemy forces rather than the coordination of supporting assets in an assault scenario.