What is the appropriate instrument used to change force structure during an operation?

The appropriate instrument used to change force structure during an operation is a Deployment Order. This document outlines the specific actions needed to deploy forces in response to operational requirements. It includes details on the units being deployed, their destinations, and the timeline, which directly influences the structure and size of forces committed to an operation.

A Deployment Order is essential as it serves as the authorization for forces to move and engage in a mission, effectively adjusting the force structure based on situational needs. It ensures that the right capabilities are in place to achieve operational objectives, aligning resources with mission requirements.

In contrast, an Operational Order is more focused on the execution of a mission rather than changing the force structure itself. A Mission Assignment pertains to outlining the duties and roles required during an operation but does not typically alter the configuration of forces. The Force Management Plan is broader and deals with strategic resource management over time, rather than the immediate adjustments necessary during an operation.