What document does the secretary of defense (SECDEF) issue to announce the selected course of action?

The document that the secretary of defense (SECDEF) issues to announce the selected course of action is an Alert order (ALERTORD). This order is utilized to notify and prepare military forces for potential action, signaling that certain plans or contingencies might be forthcoming. It's an important initial step that highlights the readiness and potential deployment of forces based on strategic requirements.

In the context of operational planning, Alert orders establish a framework for notifications without committing to a formal deployment. They serve as a way to communicate intent and readiness to various military and supporting agencies, allowing for timely preparation.

While the other document types play specific roles within military logistics and operations, they are tailored for different stages of planning or execution. A Deployment order (DEPORD) is used to authorize the actual movement of forces to a theater of operation, while a Mission directive (MISDIR) outlines specific tasks to be accomplished within an operation. An Operation plan (OPLAN) offers detailed instructions and policies for the execution of military actions but does not serve the same immediate purpose of announcing a selected course of action as an ALERTORD does.