In which level of war does a brigade fall under I Corps during an operation?

A brigade falls under the operational level of war when it is part of I Corps during an operation. The operational level bridges the tactical actions of individual units and the strategic goals set by higher command. It focuses on how to effectively coordinate and employ forces in larger campaigns and operations in support of overall strategic objectives.

At this level, commanders plan and conduct operations to achieve specific objectives within a theater of operations, utilizing the forces they command in a synchronized manner. I Corps, representing a significant component in the operational framework, typically oversees multiple brigades and other support units, influencing how they employ their capabilities in concert with broader mission goals.

Tactical warfare, on the other hand, is concerned with the execution of battles and engagements at the level of individual units like battalions and companies, focusing on immediate objectives. Strategic warfare encompasses the overarching policies and decisions that guide military efforts across multiple theaters and often involves national-level considerations. Joint operations involve the integration of forces from different branches of the military but doesn't specify a particular level of war in the context of the question. Thus, recognizing the brigade's role as part of I Corps within the framework of operational planning underscores its alignment with operational principles.