Is a Mobile Defense a Viable Option for a BCT?

By LTC Jon Anderson

Article published on: October 18, in the Winter 2024-2025 Issue of the infantry journal

Read Time: < 10 mins

Soldiers from the 2nd Mobile Brigade Combat Team, 101st Airborne Division (Air Assault) maneuver their Infantry Squad Vehicle at Fort Johnson, LA, on 16 August 2024. (Photo by SSG Joshua Joyner)

Imagine a combat credible force capable of fighting further, faster, and in the fiercest conditions, creating dilemmas for the enemy to a degree which has never been seen before: a force that is specifically designed to fight and win in severely restrictive terrain, with the ability to rapidly reposition forces with organic mobility assets across the battlefield, and that could strike deep behind enemy lines through expeditious air assault operations. This fighting force is the 2nd Mobile Brigade Combat Team (MBCT), 101st Airborne (Air Assault), and it’s changing the paradigm of large-scale combat operations (LSCO). During Joint Readiness Training Center (JRTC) 24-10, 2/101 MBCT maximized the opportunity to experiment and validate concepts in the world’s premier training environment against a fierce opposing force (Geronimo), resulting in tactical, operational, and strategic implications for the U.S. Army. While this creative approach validated many concepts within the Army’s transformation in contact concept, it also revealed unexpected outcomes. One unexpected outcome is that, through the use of the Infantry Squad Vehicle (ISV), the ability to conduct a mobile defense (a type of defensive operation typically limited to division or higher formations) is now a viable option for a mobile brigade combat team. Utilizing the operations process as a framework (plan, prepare, execute, assess), this article describes the actions of 1st Battalion, 26th Infantry Regiment during Operation Strike Fury defensive operations and how they showcased the capability of the ISV to rapidly move forces across the battlefield as a dedicated counterattack force to create conditions for the offense and allow 2/101 MBCT to regain the initiative.

Figure 1 — Mobile Defense (FM 3-90)

Overview

It is extremely rare for a brigade combat team (BCT) to conduct a mobile defense. Due to the resources required and the size of the area of operations (AO), it is not typically feasible for an element smaller than a division. However, an MBCT, when properly task organized, contains all the necessary resources to execute this type of defensive operation, to include reconnaissance assets, sustainment, and an agile command and control structure. A mobile defense is composed of three elements: the fixing force, the striking force (where the majority of the combat power resides), and the reserve. Chapter 10 of Field Manual (FM) 3-90, Tactics, states that a “mobile defense focuses on defeating or destroying enemy forces by allowing them to advance to a point where the striking force can conduct a decisive counterattack.” See Figure 1 for an example sketch of a mobile defense.

In addition to the organization’s available resources, there are three key factors stated in section 10-3 of FM 3-90 that favored a mobile defense in this scenario. The first is that frontage assigned exceeds the defending force’s capability to establish an effective area or positional defense. Second, the depth of the assigned area encourages attacking enemy forces to overextend and move into unfavorable positions where they are vulnerable to a counterattack. Third, the time for preparing defensive positions is limited. Although 2/101 MBCT did not deliberately plan a mobile defense, over the course of the operation, the brigade implemented concepts that closely resembled a fixing force and a striking force to exploit the enemy’s piecemeal attack.

Plan

The Operation Strike Fury defense was originally planned as an area defense tied to terrain in the northern and southern portions of the brigade’s AO and connected by a large natural obstacle, Red Leg Lake, in the center (see Figure 2). However, as conditions changed, to include enemy actions and the brigade’s understanding of the terrain, the agility and flexibility of 2/101 MBCT gave the commander unique options. This ultimately led to a modified plan that utilized significant portions of a mobile defense concept. The capability of the ISV proved critical to shaping the course of the battle and gave distinct advantages to the MBCT throughout the defensive operations.

The original operational concept included 2nd Battalion, 502nd Infantry Regiment (+Charlie Company, 1-26 IN operational control [OPCON]) and 1-26 IN (Bravo Company, 1-26 IN and Brazilian Pioneer Company) conducting an area defense in the north, and 1st Battalion, 502nd Infantry Regiment conducting an area defense in the south, to include a detailed deception plan using decoy emitters and proximate positioning of elements of 1-26 IN to the east and south of the AO.

The commander’s intent was to project the commitment of two battalions to the south, forcing the enemy to pursue a perceived vulnerability to the north, which would give the brigade’s main effort a distinct advantage. Upon confirmation of the enemy’s commitment of forces north, the plan was to rapidly reposition B/1-26 IN from the south to the north more than 30 kilometers utilizing their ISVs, providing a defense in depth to destroy Geronimo in detail. For reference, the ISV carries nine Soldiers, reduces Soldier load through storage of Class I and V, and can rapidly transport maneuver elements through restricted or unrestricted terrain (about 15mph in the training area at night).

Figure 2 — Operation Strike Fury Operational Graphic

With this planning consideration, 1-26 IN can completely reposition its forces more than 30 kilometers in less than 90 minutes. This addresses the issue of a BCT not normally having the resources available to execute a mobile defense; the fixing force sets conditions while the striking force maneuvers into position to close with and destroy the enemy. Additionally, the Blue Spaders implemented several tactics, techniques, and procedures (TTPs) that maximized the capabilities of the ISV while mitigating risk of exposure with the enemy. For example, while on the move, 1-26 IN utilized small unmanned aerial systems (sUAS) 500-1,000 meters in advance of its formations to identify enemy locations.

Another tactic that proved effective was to utilize the Modi system on the move when the enemy sUAS threat was likely. While at the halt, or while moving into attack positions, platoon formations would move into a herringbone formation off the road and immediately conceal their vehicles with camouflage netting. This allowed the Blue Spaders to maximize their light infantry capability by making first contact with sensors and scouts rather than driving into an ambush. This set the stage to move into the preparation of primary, alternate, and subsequent battle positions in preparation for the attack.

The operational requirements of the Infantry Squad Vehicle include the ability to carry nine Soldiers, a payload of 3,200 pounds, transportable by external sling load by a UH-60 Black Hawk helicopter, internal load/external lift by CH-47 Chinook helicopter, and exceptional mobility over all terrain, allowing infantry brigade combat teams to move with their equipment over difficult terrain. (Photo by Michael J. Malik)

Prepare

Indications showed an enemy counterattack from the southeast of the brigade, and 1-26 IN executed a fragmentary order to secure the brigade’s flank. B/1-26 IN served as the main effort for this phase and constructed four battle positions along key terrain to destroy enemy forces as they attempted to attack the brigade’s rear area. The company then utilized its ISVs to position forces along a 5-kilometer front and conducted engagement area (EA) development by integrating obstacles, fires, and key weapon systems along the enemy’s most likely avenues of approach. However, the enemy situation changed so 1-26 IN utilized its ISVs to reposition more than 175 Brazilian light infantry soldiers to the north from Berry Drop Zone to provide a defense in depth of 2-502 IN. Over the course of two 60-kilometer round-trip movements, B/1-26 IN transported Pioneer Company soldiers into their new AO, where they conducted continuous EA development throughout the period of darkness. These soldiers were positioned at the right time and place to destroy enemy forces should they break through 2-502 IN’s defense (see Figure 3, #1, for scheme of maneuver).

Execute

During the execution of the defense, Pioneer Company destroyed 14 enemy vehicles and killed more than 30 enemy in their engagement area. Concurrently, the multi-purpose company (M/1-26 IN) provided early warning and security to its northern flank through the use of its scout platoon, loitering unmanned systems (LUS) platoon, and anti-tank platoon serving as the battalion reserve. A/1-26 IN was positioned at a central location to the east of Red Leg Lake, approximately 15 kilometers from northern or southern brigade defensive positions. During the course of the battle, A/1-26 IN was committed north to the interdict the enemy’s advance upon their penetration of 2-502 IN’s defensive position, essentially serving as a striking force in the mobile defense concept. A/1-26 IN was able to occupy its battle positions in the north in under 40 minutes and in position to destroy the remnants of the enemy formation. Simultaneously, B/1-26 moved more than 20 kilometers to the south to conduct a counterattack to the rear of 1-502 IN, as the enemy showed indications of penetrating defensive positions to the south (see Figure 3, Route #2 and #3 for scheme of maneuver).

Figure 3 — This graphic depicts B/1-26 IN’s movement of the Brazilian Pioneer Company (Route #1, shown in green), B/1-26 IN’s follow-on movement to its ambush position (#2, shown in blue), and A/1-26 IN’s movement to its ambush position (#3, shown in blue).

Assess

Throughout the operation, the 2/101 MBCT commander exercised options and positioned forces in a way that the enemy was not expecting. This caused multiple dilemmas for the enemy and desynchronized their attack at echelon. Although this operation was initially planned as an area defense, the brigade executed components of a mobile defense that set conditions to rapidly transition to the offense. The ISV proved to be a decisive capability for the brigade, and the Blue Spaders demonstrated that through this platform, and the relentless pursuit of the enemy, the U.S. Army has a new way to fight and win in the most austere conditions. Without this capability, the brigade would have had limited options to exploit vulnerabilities of the enemy and would have been forced to commit to one course of action in a vast area defense. With this new level of awareness in capability, an MBCT should deliberately plan a mobile defense — properly weighting the fixing, striking, and reserve force — to find, fix, finish and follow through with destruction of the enemy.

JRTC 24-10 was truly a crucible experience for the individuals and organizations that tested themselves in the heat and pressure of Fort Johnson, LA. 2/101 MBCT used this rotation as an opportunity to experiment and innovate with new equipment and TTPs that revealed critical lessons learned for the U.S. Army. The lessons learned throughout the planning, preparation, and execution of the defense highlighted the fact that it is feasible for a MBCT to execute a mobile defense. With further refinement and innovation, this concept can be widely applied to similar formations and executed in the most austere environments. This new capability creates multiple dilemmas for the enemy, and it is changing the paradigm in how an MBCT fights. This crucible experience during JRTC 24-10 produced many tangible results, with the most important being a more lethal formation, ready to fight where we are told, to win while relentlessly pursuing our rendezvous with destiny.