When is radio silence typically implemented?

Radio silence is typically implemented as a means of preventing interception. In military operations and security situations, maintaining a low profile is crucial to avoid detection by adversaries. By refraining from using radios or other communication devices, forces can significantly reduce the risk of their positions, plans, and movements being intercepted. This strategy helps maintain the element of surprise and ensures that critical information does not fall into the hands of the enemy, thereby enhancing the safety and effectiveness of operations.

The other options don't align with the primary purpose of radio silence. Active communication would inherently contradict the practice of going radio silent. While radio silence may occur upon detection of enemy forces, it is not solely dependent on that context—it’s often a proactive measure. Lastly, implementing radio silence is not restricted to training exercises; it’s a tactical decision made during real-world operations as well.