In June 2025, a year of hard work, focused leadership, and inspired creativity culminated as the Phantom Warriors of III Armored Corps (IIIAC) successfully executed Warfighter Exercise 25-4 at Fort Hood, Texas (Fort Cavazos at the time of execution). The integration of all warfighting functions in time, space, and purpose enabled corps-level operational and division-level tactical maneuver, ultimately leading to the defeat of the enemy. Central to this success was overcoming the tendency to narrowly define the protection warfighting function as limited to physical terrain or the defense of critical assets. Instead, the IIIAC both protected to maneuver, sustain, and fire and maneuvered, sustained, and fired to protect across the breadth and depth of the Corps’ operational area. Simply telling the corps commander that the protection warfighting function was successful because nothing was destroyed, or describing risks due to limited capabilities, was insufficient for the IIIAC protection team. The introduction of protection mechanisms and protection vectors created a shared language and organizational process that enhanced the relevance of the protection warfighting function in large-scale combat operations.

Aligned with the forthcoming Army doctrine publication (ADP) 3-37, the IIIAC preserved combat power by aligning effects in time and space to optimize the allocation of limited protection capabilities, denied enemy intent by removing their capabilities from the battlespace, and enabled the corps commander’s decision making by integrating protection language and expertise into the corps’ critical path.[1] In other words, the IIIAC operationalized the protection concepts, tasks, systems, and methods of preserving combat power, denying enemy intent, and enabling the commander’s decision making by (1) treating these concepts as “mechanisms,” similar to defeat or stability mechanisms in current doctrine, and (2) organizing the domains and dimensions in a logical way for the battle staff to apply the protection mechanisms in alignment with the philosophy of the protection warfighting function.

The philosophy of the protection warfighting function differs significantly from the philosophies of other warfighting functions, particularly in the distinction between tactical protection (little “p”) and operational or theater-strategic protection (big “P”). For example, while the scope and scale differ greatly between tactical sustainment and theater-strategic sustainment, the efforts of a first sergeant to ensure that a company, battery, or troop is resourced with food, water, and ammunition are conceptually similar to the efforts of a chief of joint logistics (CJ-4) to ensure that corps and divisions are resourced. In both cases, little “s” sustainment mirrors big “S” Sustainment in its goal of delivering the right resources in the right quantity to the right place at the right time. Protection, however, is different. Little “p” protection often involves defending against threats that hinder a unit’s ability to accomplish its mission, effectively ceding the initiative to the enemy. For instance, rather than preventing the enemy from launching a missile, little “p” protection focuses on deploying air defense capabilities to shield select assets, leaving other assets at risk due to limited resources. In contrast, big “P” Protection orients protection mechanisms in time, space, and purpose to gain or maintain the initiative for friendly forces. It seeks to safeguard as many critical capabilities, assets, and activities as possible. Little “p” protection is a defensive function, while big “P” Protection is executed through the mechanisms of preserving combat power, denying enemy intent, and enabling the commander’s decision making.

Protection mechanisms are incorporated into all planning horizons, accounting for all domains and dimensions, and are aligned with the unit’s critical path for decision making, including the targeting process during conflict and decision boards outside of conflict. Protection operations, activities, and investments are oriented in time, space, and purpose through the deliberate development of a protection prioritization list. This process applies regardless of where the unit operates within the competition continuum or phase of the operation. Division-level and below organizations focus on protecting assets, while the corps prioritizes protecting capabilities and activities to enable divisions. At higher levels, combined/joint/multinational force land component commands (C/J/MFLCCs) and joint task forces (JTFs) focus on protecting capabilities to support the fight and maintain access to the theater. Key to optimizing the use of protection mechanisms in staff processes is the accountability and focus of both the core protection warfighting function staff (military police, air and missile defense, chemical, and engineer) and its extended family (cyberspace and electromagnetic activities, surgeon, communications, and safety) across all domains and dimensions.

III Armored Corps Protection
Editor’s Note: This graphic is published as originally provided by the author. No edits, alterations, or enhancements were made.

Commanders and staffs visualize protection mechanisms in terms of maintaining overmatch, relative advantage, and initiative by addressing the vectors that expose vulnerabilities in friendly critical capabilities, assets, and activities, thereby reducing the risks associated with those vectors. Field manual (FM) 4-02, Army Health System, defines a vector as a means by which disease is transmitted, typically through an insect or animal.[2] In the context of the protection warfighting function, a vector represents a means by which the enemy or natural forces could deliver negative effects to disrupt friendly operations. By orienting protection mechanisms in time, space, and purpose on these vectors, commanders can disrupt the enemy’s objectives. Additionally, the vectors provide a logical framework for organizing the sixteen primary protection tasks across the five domains and three dimensions. The IIIAC defines the vectors as follows:

• Vector #1: Space, Cyber Domains, and the Information Dimension Vector.
  Ways the enemy could impact friendly operations across the strategic and operational framework.
  Primary protection tasks: (1) cybersecurity defense, (2) electromagnetic protection, (3) operations security, (4) populace and resource control.
  Office of primary responsibility: The unit’s cyberspace and electromagnetic activities officer.
• Vector #2: Air, Maritime Domains, and the Physical Dimension Vector.
  Ways the enemy could impact friendly operations in the joint security, rear, close, deep, and extended deep areas.
  Primary protection tasks: (5) air and missile defense, (6) chemical, biological, and radiological defense, (7) explosive ordnance disposal.
  Office of primary responsibility: The unit’s air and missile defense officer.
• Vector #3: Land Domains and the Physical Dimension Vector.
  Ways the enemy could impact friendly operations in the joint security, rear, close, and deep areas.
  Primary protection tasks: (8) survivability, (9) area security, (10) physical security, (11) antiterrorism.
  Office of primary responsibility: The unit’s engineer officer.
• Vector #4: The Human Dimension Vector.
  Ways the enemy could impact friendly operations in the strategic support, joint security, rear, close, and deep areas.
  Primary protection tasks: (12) force health protection, (13) personnel recovery, (14) risk management, (15) detention operations, (16) police operations.
  Office of primary responsibility: The unit’s military police officer.

From August 2024 to June 2025, the IIIAC Phantom Warrior Protection Team worked to overcome the characterization of the protection warfighting function as confined to geographic spaces and risk analysis due to constrained capabilities. By defining mechanisms aimed at gaining and maintaining overmatch through measurable vectors, the IIIAC effectively preserved combat power, denied enemy intent, and enabled the commander’s decision making across all domains and dimensions. Protection cannot rely on reserves or just-in-time solutions; its relevance is often interpreted differently across organizations. By conceptualizing protection through mechanisms and vectors, the IIIAC achieved operational success at Warfighter Exercise 25-4—providing a model for the broader protection enterprise moving forward.