What term describes the opposing side's actions in response to a commander's plan?

The term that best describes the opposing side's actions in response to a commander's plan is "Reactions." In military strategy and tactics, when one side devises a plan or takes action, the other side must assess and respond to those actions, which constitutes their reactions. These reactions can vary widely based on the nature of the original commander's plan, the goals of the opposing side, and the context of the engagement.

This term emphasizes the idea that the opposing side's actions are directly influenced by the initial plan, as they aim to counter or adapt to what has been proposed by the commander. Understanding this concept is crucial, as it highlights the dynamic nature of strategic planning in military operations, where each side is continuously responding and adjusting their tactics based on the actions of the other.

In contrast, while terms like "Counteractions," "Deterrents," and "Responses" seemingly capture similar concepts, they may lack the specific context that "Reactions" offers in defining how one side specifically responds to another's operational initiatives.