Key point: Counterinsurgency operations have put troops at risk in unprecedented ways.
The design of an armored vehicle always involves a triple compromise called the Iron Triangle between protection, mobility and firepower. Infantry fighting vehicles (IFVs) have traditionally focused on mobility and firepower, placing less emphasis on protection. But recent trends in conflict have begun to change that, as IFVs mount bigger and bigger guns and pack more and more armor. A new class of vehicles is emerging: the heavy IFVs.
Early IFVs were significantly more mobile than most main battle tanks (MBTs) of their day. Unlike the T-55 and T-62, the BMP-1 could float on rivers and move faster on and off the road. But the designers didn’t neglect the “combat” aspect either, since it was supposed to be able to face most CCPs of the time in ambush with its Malyutka Anti-Tank Guided Missile (ATGM). The American M2 Bradley was also amphibious and could handle tanks with its TOW ATGM.
The big compromise they made was that they weren’t well armored at all. Bullets from a .50 caliber machine gun could slice through the side of a BMP-1 like butter and although the front was tougher, almost any tank gun passed through it.
As the main task of these vehicles was to support infantry, this level of armor was considered acceptable. Vehicle mobility and firepower were considered more important as these early IFVs were designed to fight on a mechanized Cold War battlefield.
The key roles of the IFV were to provide nuclear, biological and chemical protection to troops, to protect them from small arms and artillery, and to pack a bigger punch on the battlefield than the infantry itself could carry.
Adding more armor wouldn’t make them much more effective in their role, and it would compromise their tactical mobility by getting rid of their fast fording and swimming aspects. Soviet doctrine emphasized this capability: when crossing a water obstacle, BMPs were supposed to cross first and secure the opposite bank before tanks attempted to snorkel or dive. be transported.
In the early 1980s, the Soviet BMP series saw combat for the first time. Thin armor originally intended for Cold War mechanized warfare proved too thin. As a result, the Soviets chose to sacrifice river crossing capability and some speed in exchange for more armor in the D variants of the BMP-1 and BMP-2.
The D did not completely replace the regular BMP-2 variants, and the next BMP, the BMP-3, still retained the amphibious capability. Still, the trend foreshadowed what might happen in the future with IFVs.
In 1988, the United States also sacrificed the river crossing capability of the Bradley in the M2A2 version. Additional armor was added to the side to protect against larger caliber ammo and shrapnel. Unlike the Soviets, other versions of the Bradley did not restore amphibious capability.
Instead, American designers added more and more armor and equipment to the Bradley. The original Bradley weighed about twenty-seven tons; by the M2A3 variant, the Bradley weighed thirty-two tons with additional explosive reactive armour.
Armor augmentation was not just an American and Soviet thing. The Germans also began to show interest in heavier models. Towards the end of the Cold War, the Federal Republic of Germany planned to replace its Marder 1 IFVs with the Marder 2. This beast of an IFV had enough armor to stop a round tank and weighed forty-three tons, plus than the first T-72s. It also contained a thirty-five millimeter cannon which was far more powerful than any other IFV cannon of the time.
This trend of steadily increasing gun and armor weights for IFVs has continued to the present day, where Russia is considering making an IFV version of the Armata with the T-15. Germany also continued the legacy of the Marder 2 with the slightly less armored but still heavy Puma IFV.
But what is driving these trends for these increasingly heavy VCIs? The tactical advantages of mobility and speed that originally characterized the IFV no longer apply to these new vehicles, as they move at the same speed as tanks and are not amphibious.
One possible reason is an arms race against armor with IFVs. IFVs are often expected to fight other IFVs, so the weight of armor on them has increased as the caliber of IFV weapons has increased. The current M2A3 Bradley is protected against the BMP-2’s thirty-millimeter gun on the frontal arc, while the original M2 Bradley was only protected against a BTR’s 14.5mm heavy machine gun.
Another possible reason is the switch to COIN. In COIN, casualty mitigation is more important than speed or tactical mobility, so there is a strong incentive to weaponize existing platforms. While IFVs were originally designed to fight infantry outside of the range of shoulder-launched AT weapons like the RPG, COIN can push them into those tight infantry engagements, so the armor becomes more important. The overall downsizing of armies also makes it cheaper to purchase such heavy (and expensive) IFVs, as most armies no longer need to deploy multiple divisions of them.
Information on BMP tactics taken from the British Army Field Manual, Volume 2, Part 3: Soviet Tactics.
Charlie Gao studied political and computer science at Grinnell College and is a frequent commentator on defense and national security issues. This article first appeared last year.