Intro to Infantry Doctrine

If you understand the basis of the Second Amendment to the United States Constitution, then you shouldn’t have to ask why we’re going over infantry doctrine. If you’re left wondering what that means —and I say this with genuine respect— I implore you to do some research about the US Constitution and the history of our founding. It’s an eye-opening experience and reinforces why citizens need to have this knowledge.

Many that read this may dismiss it as not applicable to them. After all, they aren’t in an infantry company and don’t have access to the same arsenal. While that’s true, there is valuable information to be found that can be scaled to your needs. You don’t need to have belt-fed machine guns to understand establishing a base of fire and the principles of shooting, moving and communicating. These are valuable skillsets that can be used with many weapons under a variety of conditions.

Having the knowledge of these skillsets is not simply for implementing violence but to educate and enable citizens to recognize what they are seeing if they were to ever witness the extreme. US doctrine will be explained here, but after truly understanding it, the concepts can be applied to other forces even though they may differ. Many countries have conscription for this purpose (not necessarily saying I agree with that) but it’s always better to be a warrior in a garden than a gardener in a war. Ukraine learned this fact a little too late when they started unloading crates of AK’s to an untrained populace out of desperation.

With that out of the way, we’re going to begin learning the basics. Many like to start with learning tactical formations and hand signals first, since these are the foundations of moving and communicating as a team. However, when I was first exposed to this material, I found it to be a little too abstract without fully understanding roles. For example, I understood where the SAW and grenadier should be in a fireteam wedge, but I didn’t know exactly what the positions entailed or what they actually do if the team receives contact. Hopefully, by learning roles first you will be given more context and clarity when looking at the more abstract tactical concepts in the future.

In saying that, we will begin learning the roles of each person in a fireteam, squad, and platoon. While we’re discussing this, please keep three things in the back of your mind. First, this is from an Army infantry perspective. Marines do things a little differently in terms of element sizes and weaponry used, but the basics are still the same. Second, know that the roles, ranks associated with them, and element sizes that will be mentioned are by-the-book and are subject to change in reality; i.e., it’s not uncommon for specialists to be team leaders or fireteams to be 5 instead of 4. Third, please understand that infantrymen are only as good as the support behind them. I say this not to be nice but to reiterate that infantrymen cannot sustain themselves alone while carrying out their roles long term. Every Joe needs bullets, beans, band aids, and batteries, so someone has to be in the background working on the logistics. No matter what the mission is, it has to be sustainable. Many battles have been lost because of supply line issues. With this understanding, let’s begin.

RANKS

FIRETEAM: an element of 3-5 soldiers

• Team Leader (Sergeant/E5): Uses the M4A1. Most senior on the team. Receives and implements orders from the squad leader. Dictates the speed and direction while maneuvering. Responsible for emplacing personnel in their positions. Provides precision fire where necessary.
• Automatic Rifleman (Specialist/E4): AKA SAW Gunner. Uses the M249 Squad Automatic Weapon. Takes over if TL is killed. Second most senior on the team due to the difficulty of using and maintaining the LMG (light machine gun) and the physical demands placed on the soldier. Used to suppress the enemy and carries the weapon allegedly responsible for 75% small arms casualties to the enemy (source: trust me, bro). Unlike 240 gunners, SAW gunners maneuver alongside the fireteam and are expected to keep up with the other riflemen. The responsibility is not taken lightly.
• Grenadier (Private-Specialist/E2-E4): Uses the M4A1 with the M203 or M320 grenade launcher. Most M203’s can only be used mounted to the rifle versus the M320 which can be mounted or used as a standalone weapon. Due to its added bulk, many prefer to use the M320 standalone if possible. Third most senior on the team and takes over if the team leader and SAW gunner are killed. Used to engage combatants in defilades or buildings where bullets cannot penetrate. Can use a variety of 40mm munitions but the most common is the HE (high explosive) round. Adds a considerable capability in varying terrain.
• Rifleman (Private/E2-E3): Uses the M4A1. Typically, the least experienced on the team and carries the bulkier/heavier items like the Skedco (litter), AT4, or the CLS (combat lifesaver) first aid bag since their loadout is lightest. Used to provide precision fire where necessary.

SQUAD: an element of 6-10 soldiers (2 fireteams and the squad leader)

• Squad Leader (Staff Sergeant/E6): Uses the M4A1. Most senior of the squad. Receives and implements orders from the platoon leader. Dictates the direction and positioning of the fireteams while maneuvering. Responsible for ensuring the fireteams (Alpha & Bravo) work cohesively, avoiding fratricide, carrying out the objective, and maintaining comms with the platoon. Typically stays in the middle of tactical formations to more effectively lead both teams. If all goes to plan, the squad leader will barely shoot, if at all, since his priority is to lead first.

SPECIALIZED SQUAD: Weapons Squad (usually 4^th squad). An element of 6-10 soldiers comprised of 2 gun teams and 2 missile teams led by a squad leader. Typically, does not close with the enemy like the other squads so they can provide important suppressive fire. They also lack the maneuverability of other squads because of the weapon systems. Every role in this squad is crucial to a platoon’s success.

• Squad Leader aka WSL (weapons squad leader) pronounced “weasel” (Staff Sergeant/E6): Uses the M4A1. Most senior of the squad leaders tasked with leading 70-80% of a platoon’s firepower. Leads the gun teams by strategically emplacing them on or near the objective to provide suppressive fire and enable freedom of maneuver to the other squads
• 240 Gunner x 2 (Private-Specialist/E2-E4): Uses the M240B/M240L and or the M9/M17. Responsible for most of a platoon’s firepower. Typically sets up at a more static position and provides support by fire on an objective to suppress the enemy so the other squads can move. Angriest guy on patrol, happiest in a firefight.
• Assistant Gunner (AG) x 2 (Private-Specialist/E2-E4): Uses the M4A1. Directs fire of the 240. Depending on the SOP, is usually most senior on a gun team. Helps setup the tripod/T&E and links ammo as the gunner shoots. Helps perform barrel changes when necessary. Assumes the gunner role if the 240 gunner is killed. Carries the tripod/T&E, spare barrel, and some ammo.
• Ammo Bearer (AB) x 2 (Private-Specialist/E2-E4): Uses the M4A1. Carries ammo for the gun team plus anything else necessary. Typically, greenest on the team, also known as “ammo bitch”.
• Javelin Gunner x 2 (Private-Specialist/E2-E4): carries the M4A1 and Javelin. Provides anti-vehicle capability to the platoon. Making another reference to Ukraine, this guy makes even light infantry units a serious threat to any vehicle, including APC’s (armored personnel carriers), tanks, low-flying helicopters, and there are some unverified reports of even some fighter jets (although not its intended purpose).

PLATOON: an element of 24-50 soldiers (4 squads, the platoon sergeant, and the platoon leader)

• Platoon Sergeant (Sergeant First Class/E7): Uses the M4A1 and or the M9/M17. Helps lead the squad leaders and oversees the objectives of the platoon. Most senior enlisted member of a platoon. Works hand-in-hand with the Platoon Leader and many times runs the show when necessary. If this man is shooting, things have gone really bad.
• Platoon Leader (2^nd-1^st Lieutenant/O1-O2): Uses the M4A1 and or the M9/M17. Ultimately leads and is responsible for the successes and failures of the platoon. Writes OPORDs, plans missions, and handles logistics. Views things through a more strategic vs tactical lens. Carries out the commander’s intent of the mission and ensures the platoon understands it. Authorizes and calls in support via mortars, artillery, or air if necessary. Needs to consider not only the lives of his men but also collateral damage to civilians and infrastructure if necessary. If this man is shooting, things are probably so bad that someone is getting a medal.
  • Specialized Platoon Positions
    • RTO (Radio Telephone Operator) (Private-Specialist/E2-E4): Uses the M4A1 and carries a radio. Helps the platoon leader communicate with command at the TOC (Tactical Operations Center). Can easily be recognized because they look like a RC car with an antenna sticking up. This guy is the right-hand man of the platoon leader and is never far from them.
    • Squad Designated Marksman (Private-Specialist/E2-E4): Uses an accurized version of the M4A1 or M16 or a purpose-driven rifle like the M110A1, or the MK12 and MK14 (old school). FYI, we aren’t getting into the semantics of DMR/SPR/Recce configurations here. Often confused as a sniper to untrained eye, this person has extra marksmanship training, but is not trained in fieldcraft like a sniper is. Usually embedded at the squad level to provide precision fire at distances greater than the average squad can provide. Max engagement distances are around 6-700m versus 1000m+ like snipers with specialized training and higher caliber weapons. By 2023, the Army would like a designated marksman in each squad with the new HK M110A1.
    • Defactos and Backups (varies): Often people are expected to perform numerous roles in case a platoon is shorthanded or if it takes casualties. Many times, more squared away individuals can call fire missions or 9 line MEDEVACS in, for example.

• Squad Roles
  • 1^st Squad: Assault Squad. Usually, the most aggressive and lethal squad that is first on the objective. First through the breach and the hungriest. Leads platoon patrols. Casualties can be high with a prepared foe. They know why they signed up.
  • 2^nd Squad: Assault Squad Backup or Simultaneous Assault Squad. Provides a close backup for 1^st squad or can simultaneously assault alongside 1^st squad if the objective is big enough or if there are multiple objectives. Fairly squared away.
  • 3^rd Squad: QRF or Simultaneous Assault Squad. Typically, stays around the perimeter to cordon off the area and pull security against flanks or reinforcements. Will respond if 1^st or 2^nd squad needs them. If objective is really big, they’ll simultaneously assault alongside 1^st and 2^nd. Not usually the most squared away but can be just as deadly.  
  • 4^th Squad: Weapons Squad. Gun emplacements along main avenues of approach and provides support by fire on or near the objective. They are the lifeline of the platoon and enable maneuverability by suppressing the enemy.

To reiterate, these are generalities and can vary based on unit SOP, but they are the basic rank and structure of an infantry rifle platoon. I’m sure Mech/Heavy infantry, Cavalry, and even some light infantry units are foaming at the mouth at perceived inconsistencies to their doctrine. This is a bird’s eye view, not a patrol through the weeds.

For those wondering why larger elements, such as companies or battalions, aren’t covered, there is a simple answer. Learning is foundational and this is no exception. Once you have a firm grasp on these smaller elements, you can study even more, maybe even play Risk in your head with division-sized elements (I don’t even know all of that). And pragmatically, if you’re reading this from the perspective of a concerned citizen, anything larger than a fireteam or squad really shouldn’t be considered without serious planning and preparation.

If this turns out to be popular for those tired of reading boring field manuals, then I’ll continue it. Stay tuned for potentially more information, like conducting fireteam, squad, and platoon level movements, and patrol base operations.