In April, the Army unveiled a new model of its mainstay armored vehicle: the M2 Bradley infantry fighting vehicle (IFV), which both transports infantry and supports them in combat using a rapid-firing Bushmaster 25-millimeter autocannon and long-range TOW-2 anti-tank missiles.
The new M2A4E1 subvariant sports a potent new Israeli-designed Iron Fist âhard-killâ active protection system. It uses radar and infrared sensors to detect incoming anti-tank projectiles, and shoots them down before they can impact the vehicle using four grenade-like counter-munitions preloaded in two small turrets bolted onto the Bradley.
While Bradleys are well-armored compared to other IFVs, their armor is still weaker than that of a main battle tank, and there are still many higher-end tank-busting weapons likely to knock a Bradley out with one hit.
But with Iron Fist, Bradley crews now can pull some âget-out-of-jail-for-freeâ cards when targeted by powerful anti-tank guided missiles (like Russia's Kornet), lighter unguided rockets (like the ubiquitous RPG-7), old-school recoilless rifles (like the Soviet SPG-9), and kamikaze drones.
The E1 model also incorporates a cooling system (ECU) to keep passengers chill, and a new third-generation, high-definition forward-looking infrared (HD FLIR) gunnerâs sight offering greatly improved resolution and low-light performance. That should further widen the marked spotting advantage that Bradleys have demonstrated over Soviet armored vehicles in Iraq and Ukraine.
The M2A4E1 subvariant was always the end goal in the Armyâs plans to modernize the Bradley, but before the service could bolt-on Iron Fist and the new FLIR, it needed to complete development of an M2A4 Bradley model with the increased engine power and electrical capacity necessary to handle the new systems.
Israeli company Elbit has reportedly been awarded $37 million to furnish General Dynamics Land Systems with Iron Fists for M2A4E1s over the next two years, though this is just a fraction of the upgradeâs total cost.
The Army says that it has received funding to upgrade one Bradley to the new M2A4E1 model for every Bradley donated to Ukraine. But that characterization risks being misleadingâthe over 200 M2A2-ODS Bradleys given to Ukraine (a total soon set to increase following the resumption of U.S. military aid in April) were drawn from the collection of over 2,000 older M2 Bradleys in storage, not the roughly 2,500 M2 Bradleys in operational service (a mix of M2A2s, M2A3s and now a few dozen M2A4s). Rather, it seems the Army is commenting on new âefficienciesâ in funding the Iron Fist upgrade that donations to Ukraine may have unlocked.
For now, funding suffices only to upgrade âdozensâ of Bradleys. But the Army plans to eventually field 1,242 Iron Fist-equipped Bradleys in nine brigades, with priority going to units in Europe should a ground war erupt with Russia. Thatâs roughly half of the M2s currently in U.S. Army service (or one-third, counting the similar M3 Cavalry Fighting Vehicle variant).
How Iron Fist Works
Iron Fist Decoupled-Light (IF-LD) weighs 725 pounds altogether, and consists of four small wedge-shaped radar panels, two launchers on small rotating turrets (each with two grenade-like counter-munitions loaded), four boxy dual optical HD/infrared camera sensors, and three internal elements. The external components can be bolted on without penetrating inside the vehicle, and require 610-820 watts of electricity to function.
The radars and optical sensors individually cover a 90-degree arc, and thus together provide 360 degrees of coverage to spot incoming threats. The combo of radar and optical sensors also improves accuracy and provides redundancy, should environmental conditions or enemy countermeasures particularly degrade the efficacy one type of sensor. Reportedly, Elbit also claims that the company has worked to âstealthâ Iron Fistâs radar emissions so that they donât give away the location of the carrying vehicleâa matter of prior concern to the U.S. Army.
When Iron Fistâs sensors detect an incoming object that appears to be an accurate threat, one of the two launchers calculates an intercept trajectory and fires a grenade-like counter-munition with pop-out tail fins. This interceptor flies to a position parallel to the incoming missile or rocket before exploding, and the resulting shockwave shatters the anti-tank projectile before it can discharge its armor-piercing shape-charged (HEAT) warhead.
As the detection-to-launch cycle can be executed within 300-350 milliseconds, Iron Fist is deemed capable of intercepting attacks from as close as 50 meters (half a football field) away. Furthermore, as all Iron Fist shots are preloaded, the system can defend against two attacks simultaneously, or four in rapid succession before its counter-munitions are spent.
Additionally, Iron Fistâs optical sensors can detect and localize flashes from small arms fire, enabling the vehicle crew to rapidly suppress such threats to friendly infantry.
Iron Fistâs Rocky Road to Service
Middle Eastern wars in the 2000s and 2010s suggested that infantry anti-tank weaponsâboth short-range rocket and (more acutely) heavier anti-tank guided missiles (ATGMs) that were effective from 2 to 3 miles awayâwere likely to be the primary killers of tanks in 21st century battlefields.
Israeli procurement of a âhard-killâ active protection system called Trophy (by Israeli company Rafael) was notably accelerated by the effectiveness of Russian Kornet missiles against the Israeli armored corpsâ well armored Merkava tanks in a 2006 war with Hezbollah. Trophy proved so effective in the IDFâs conflicts with Hamas in the 2010s that it was only a matter of time before APSs were integrated onto Western M1 Abrams and Leopard 2 main battle tanks.
However, Trophy faced competition from rival hard-kill APS systems, including the American Iron Curtain system and the Israeli Military Industries (IMI) Iron Fist, which received substantial input from German company Diehl (developer of the similar, concurrent AVeP APS).
When the U.S. Army tested various APSs on Bradley fighting vehicles, Abrams tanks, and Stryker wheeled armored personnel carriers, it decided to procure Trophy for the Abrams and the Iron Fist Light variant for the Bradley. The Army wasnât satisfied with Iron Curtain for the lighter Stryker.
Perhaps Iron Fistâs small explosive projectiles were deemed to pose less risk to nearby infantry than the explosively formed fragments (EFFs) used in Trophy that project a cone-shaped zones of destruction like a shotgun blast. Reducing collateral risks would be an important consideration for a troop-carrying vehicle.
Additionally, Iron Fistâs launchers can be placed more flexibly, and its additional ready-to-fire counter-shots would reduce the effectiveness of tactics devised to defeat Trophyâtactics like launchers designed to shoot two missile near simultaneously, the first intended to absorb the Trophy shot so that the second impacts before Trophy can reload.
However, initial testing of Iron Fist-Light on M2A3 Bradleys in 2018 (modified with extra electrical capacity) revealed âinconsistent capability to intercept threats,â according to a Pentagon report. âCounter-munition dudding and power failures to the launcher were leading contributors to the low intercept rate.â Reportedly, it countered just 50 percent of incoming threats.
The service hit the brakes on integrating Iron First further until a significant redesign of both the installation and the counter-munitions had been completed, resulting in the present Iron Fight Decoupled-Light.
The systemâs software includes algorithms to discriminate against firing at âfalse positiveâ targets, and the systemâs open architecture and modular design may mean its targeting algorithms could be more easily upgraded and updated in response to new threats like FPV kamikaze drones.
A follow up report states that IF-LD âdemonstrated improved performanceâŚâ in extensive tests in 2022, but ââŚcontinues to face effectiveness deficiencies.â Another account states that it proved effective against 70% of threats under more difficult testing conditions than in 2018, involving operationally realistic environments that included inclement weather, buildings, and friendly vehicles nearby.
The report notes that Bradley crews specifically requested the ability to selectively disable Iron Fistâs coverage in specific arcs when mounting and dismounting soldiers, as well as the capability to alert the crew of near-miss attacks so they can fire at the attackâs point of origin. Whether such features have been or will be implemented is unclear.
Refinement of IF-LD for the Bradley finally led to its adoption on other vehiclesânotably, the IDFâs new IAI Eitan eight-wheeled APCs, which saw its combat debut last October, and the D9 âPandaâ armored bulldozers used to demolish Palestinian homes. The Royal Netherlands Army began outfitting its 128 CV9035NL tracked infantry fighting vehicles with IF-LDs in 2021 as part of a mid-life upgrade, while Spainâs forthcoming fleet of 348 Dragon VCR eight-wheeled infantry fighting vehicles (based on the MOWAG Piranha 5) will also bolt Iron Fist onto their Guardian 30 gun turrets. There is a further simplified Iron Fist variant called Iron Fist Light Configuration (IF-LC) that mounts a launcher, sensors, and a control unit on a singular, all-in-one pedestal
Itâs worth noting that Iron Fist Light doesnât include two capabilities of the heavier original Iron Fist system: a backup âsoft-killâ infrared jammer/dazzler to lead optically-guided missiles astray, and larger counter-projectiles capable of degrading the penetration of supersonic kinetic-energy tank shells (if fired from a distance of probably 600 meters or more).
Such powerful rounds have too much kinetic energy to be stopped cold, but the projectileâs angle of penetration might be diverted and its impact velocity reduced sufficiently to avert lethal penetration. Apparently, even tilting a kinetic penetrator 10% off-angle can reduce effective penetration by as much as 50%.
However, another âlightâ variant called Iron Fist Light-Kinetic (IF-LK) demonstrated the ability to deflect a powerful 120-millimeter tank shell in a test. Perhaps it uses the standard Iron Fistâs larger counter-munitions, but not the soft-kill dazzler.
Just How Well Can Iron Fist Punch Drones?
Ironically, Russiaâs invasion of Ukraine revealed a different âbreakoutâ anti-tank technology than expected: small drones, both civilian quadcopters adapted to drop anti-tank grenades from above, and cheaper first-person view drones refitted to ram kamikaze fashion into armored vehicles while carrying an RPG warhead.
By 2024, drones had reportedly come to account for the majority of armor losses in Ukraine. Though slower than missiles, they are typically more than an order of magnitude cheaper and (unlike most portable missiles) can harry tanks many miles behind the frontline. Furthermore, skilled FPV drone pilots can maneuver to hit moving targets and attempt to strike weak points in even well-protected tanks.
While Active Protection Systems werenât originally designed to kill dronesâthey didnât emerge as common threat until around 2014âthereâs reason to believe they might be pretty effective with some modest modifications. After all, small drones are much slower than missiles, affording APSs plenty of time to detect their approach and calculate targeting solutions. Drones dropping grenades from above may differ more in approach, but a gravity-dropped grenade is still not moving all that fast.
Thus, getting APSs to kill drones may simply involving ensuring their sensors and fire control systems are programmed to recognize drones as threats (despite differing from missiles in shape and speed) and calculating intercepts accordingly.
A demonstration in Israel showed that a Bradley with IF-LD could in fact defeat simulated kamikaze drones (a.k.a. loitering munitions). Reportedly, Iron Fistâs sensors can detect drones up to a mile away and pass that info through networking to other air defenses to have a first crack it. After all, an APS is much like a soccer teamâs goalieâa potent last-ditch defense, but (ideally) not the only defense.
However, APSs sensors and counter-measures designed to defeat missiles flying in relatively shallow trajectories may have a âblindspotâ for vertical attacks coming in from directly above the vehicle, as they lack the ability to elevate a full 90 degrees. That, by definition, would include drones gravity-bombing from above with anti-tank grenadesâa method both used by Hamas drones to knock out a crewed Israeli Merkava tank at the onset of the Gaza War, and extensively employed in Ukraine. FPV drones may also attempt high-angle âdive bomb attacks,â though these are trickier for operators to execute.
Specifications for Iron Fist in the past stated a maximum 80-degree vertical protection arc, meaning that it did have a vertical blind spot. Perhaps the modifications to Iron Fist Light-Decoupled increased the vertical engagement. Itâs unclear whether promotional material stating Iron Fistâs âhigh elevation angleâ means full vertical coverage.
The Bradleyâs Epic 60-Year Metamorphosis
Development of the Bradley began in 1960s in reaction to the Soviet Unionâs ground-breaking BMP-1 infantry fighting vehicles. Entering service in the 1980s after a troubled and expensive development, Bradleys performed well once they saw action in the 1991 Gulf War, allegedly destroying more Iraqi armored vehicles than the Armyâs Abrams tanks did.
All in all, over 6,785 Bradleys were produced at an average price of $4 million each (using 2022 adjusted dollars). Of these, 4,641 were procured by the U.S. Army and the remainder were exportedâ400 to Saudi Arabia, smaller quantities to both Croatia and Lebanon.
Armored cavalry units use a model nearly identical to the standard M2 Bradley Fighting Vehicles used by mechanized infantryâthe M3 Bradley Cavalry Fighting Vehicle, which differs only in that it has additional radios, reduced passenger seating, and an increase in TOW missile stowage capacity (from two to 12). There are over 1,200 M3A2s and M3A3s in service, and another 800 M3s in storage.
The Army also operates over 330 M7 Bradley First Support Vehicles (BFIST) sans missile launchers for spotting targets for artillery fires. Furthermore, a Stinger-missile armed air defense model called the M6 Linebacker served until 2006 before being converted back to the M2A2-ODS configuration.
Compared to others IFV designs, the Bradley is particularly heavy and well-protected, though it lacks the capacity to carry more than 6 or 7 passengers. Over the years, Bradley models received additional armor, increasing weight from 27 to 33 tonsâparticularly in the form of explosive reactive armor (ERA) bricks adept at defeating the shaped-charges used in portable anti-tank munitions. You can see the ERA fitted to a Ukrainian Bradley defeating a missile and a drone attack below.
But a problem remainedâup-armored Bradleys didnât receive increased engine power and other modifications to compensate for added weight, and therefore suffered from inadequate engine power, low ground clearance (not only worsening mobility, but increasing passenger vulnerability to mines and IEDs), and insufficient electrical-generation and cooling capacity to support systems like Iron Fist or more powerful radios.
These problems were solved in two phased âEngineering Change Proposals,â which combined resulted in the M2A4 Bradleyâthe first of which entered service in 2022. Notably, a new HMPT-800-3ECB hydraulic transmission combined with a Cummins VTA903E 675-horsepower eight-cylinder diesel engine restored mobility and expanded electrical capacity enough to eventually install Iron Fist and the new infrared sensor.
Other M2A4 enhancements included heavier-duty suspension and torsion bars increasing ground clearance 34% to 20 inches, a new jammer to disrupt cell-phone triggered IEDs, a new internal fire suppression system, and added digital displays and datalinks for networking sensor information with friendly forces.
Eventually, a new IFV called the XM30 MICV with a much bigger 50-millimeter gun, a two-person crew, autonomous navigation capabilities, and hybrid-electric engine is slated to replace the Bradleyâa process slated to start in 2029. The XM30 MICV will likely incorporate APS.
Thereâs little doubt that Iron Fist constitutes a major improvement to the Bradleyâs survivability in combat, even if it canât address all threatsâvulnerabilities to things like anti-tank mines/IEDs (a primary cause of losses in Iraq) and tank or artillery shells remain. The systemsâ potential to bat away drones is of particular interest, given that small, extremely cheap drones seem poised to become one of the most important anti-tank weapons of the 21st century.
SĂŠbastien Roblin has written on the technical, historical, and political aspects of international security and conflict for publications including 19FortyFive, The National Interest, MSNBC, Forbes.com, Inside Unmanned Systems and War is Boring. He holds a Masterâs degree from Georgetown University and served with the Peace Corps in China. You can follow his articles on Twitter.
