What qualifies a patrol to conduct a "reconnaissance by force" mission?

A patrol qualifies to conduct a "reconnaissance by force" mission primarily through offensive actions aimed at gathering information through engagement. This type of reconnaissance is characterized by proactive measures where the unit engages the enemy directly to assess their capabilities, strengths, weaknesses, and overall disposition. The intent is not merely to observe, but to provoke a response that can be analyzed for intelligence purposes.

Engaging the enemy allows the patrol to gather real-time information and confirm or deny intelligence gathered from other sources. This method is particularly useful when there is uncertainty about enemy locations or strength, as it provides immediate and actionable intelligence that traditional observation methods might not yield. By forcing the enemy to respond, the patrol can also determine the level of enemy activity and readiness.

The other options, while related to different aspects of patrolling and intelligence gathering, do not align with the specific requirements or intent of a reconnaissance by force mission. For instance, defensively assessing enemy strength focuses more on observation and less on engagement; establishing a permanent observation post implies a static approach instead of an offensive one; and maintaining strict radio silence is contrary to the communications needed for coordinating and reporting during an aggressive engagement.