Mechanized infantry
As early as 1915 the British instigated a tracked vehicle that could carry 50 equipped troops under armour but the project got no further than trials before cancellation.
During the battle, tank crews were reported to have dismounted and attacked enemy positions with grenades and flamethrowers on numerous occasions.
Another example is the capture of Villers-Bretonneux, in which A7Vs suppressed the defenders with machine gun fire and assault teams dismounted to attack them with grenades.
Tanks, artillery, or infiltration tactics could all be used to break through an enemy defense, but almost all offensives launched in 1918 ground to a halt after a few days.
Motorized infantry could maintain rapid movement, but their trucks required either a good road network or firm open terrain, such as desert.
The French Army also created "light mechanized" (légère mécanisée) divisions in which some of the infantry units possessed small tracked carriers.
The German doctrine was to use them to exploit breakthroughs in Blitzkrieg offensives, whereas the French envisaged them being used to shift reserves rapidly in a defensive battle.
In the British and Commonwealth armies, "Type A armoured brigades," intended for independent operations or to form part of armored divisions, had a "motor infantry" battalion mounted in Universal Carriers or later in lend-lease halftracks.
Because the German economy could not produce adequate numbers of its half-track APC, barely a quarter or a third of the infantry in Panzer or Panzergrenadier divisions were mechanized, except in a few favored formations.
The Red Army began the war while still in the process of reorganizing its armored and mechanized formations, most of which were destroyed during the first months of the German Invasion of the Soviet Union.
Red Army mechanized infantry were generally carried on tanks or trucks, with only a few dedicated lend-lease half-track APCs.
The New Zealand Army ultimately fielded a division of a roughly similar composition to a Soviet mechanized corps, which fought in the Italian Campaign, but it had little scope for mobile operations until near the end of the war.
Armored vehicles meant infantry were capable of overcoming water barriers and having means of protection against Weapons of Mass Destruction.
The US Army established the basic configuration of the tracked APC with the M75 and M59 before it adopted the lighter M113, which could be carried by Lockheed C-130 Hercules and other transport aircraft.
[13][14] The introduction of the BMP-1 prompted the development of similar vehicles in Western armies, such as the West German Marder and American M2 Bradley.
In the Soviet Army, a first-line "motor rifle" division from the 1970s onward usually had two regiments equipped with wheeled BTR-60 APCs and one with the tracked BMP-1 IFV.
[15] A line of development in the Soviet Armed Forces from the 1980s was the provision of specialized IFVs for use by the Russian Airborne Troops.
That made airborne formations into mechanized infantry at the cost of reducing their "bayonet" strength, as the BMD could carry only three or at most four paratroopers in addition to its three-man crew.
Infantry units equipped with IFVs rather than lighter vehicles are commonly designated as "heavy", indicating more combat power but also more costly long-range transportation requirements.
Such vehicles are usually expedients, and lack of space prevents the armament of an IFV being carried in addition to an infantry section or squad.
In the Russian Army, such vehicles were introduced for fighting in urban areas, where the risk from short range infantry anti-tank weapons, such as the RPG-7, is highest, after Russian tank and motor infantry units suffered heavy losses fighting Chechen troops in Grozny during the First Chechen War in 1995.
Some of the latest designs (such as the German Puma) are intended to allow a light, basic model vehicle, which is air-transportable, to be fitted in the field with additional protection, thereby ensuring both strategic flexibility and survivability.
In the late Cold War and early 21st century, various countries developed medium infantry forces armed with armored vehicles, which typically consisted of wheeled armored personnel carriers, infantry fighting vehicles, and assault guns.
Medium mechanized forces are characterized by having more strategic air and road mobility than heavier, tank-based armored forces while offering better armor protection for the formation than the lighter motorized infantry formation, in which vehicles were considered "battle taxis" due to poor protection.
The earliest experiment was the short-lived Soviet Light Motor Rifle Division in 1987, which consisted of wheeled BTR platforms for its primary armament.
[17][18] It is generally accepted that single weapons system types are much less effective without the support of the full combined arms team; the pre-World War II notion of "tank fleets" has proven to be as unsound as the World War I idea of unsupported infantry attacks.
