Sponge Bombs in the Gaza Metro?: Israel’s Counterinsurgency Campaign

Sponge Bombs in the Gaza Metro?: Israel’s Counterinsurgency Campaign

by AJ Milla

If you’ve found yourself confused by the headlines of an Israeli “SpongeBob” lately, we’re here to clear up some confusion.

No, Nickelodeon hasn’t begun exporting Zionist propaganda about military tactics involving a pineapple under the sea and a sponge-man debating a two-state solution. What you’ve mistakenly heard about is an Israeli “sponge bomb”.

Similarly, much like an underwater pineapple, the sponge bomb facilitates an oxygenless environment for its inhabitants. Though, unlike a pineapple under the sea, the sponge bomb actually exists and presents an existential threat.

Have we lost our minds? What are we talking about?

Grab your snorkels and carrier plates–truth is stranger than fiction.

Israeli Defense Forces entering inside the Gaza Metro.

Israeli Defense Forces penetrating the Gaza Metro. (Image courtesy of The Lieber Institute)

Table of Contents

  • 01

    I’m ready, I’m ready

  • 02

    The Gaza Metro

  • 03

    Looking for the light

  • 04

    “Ravioli, ravioli. Give me the formuoli!”

  • 05

    Sticky situations

  • 06

    MIRA Safety, Is The Safety Solution for You and Meeeeee

  • 07

    Wrapping Up

  • 08

    Frequently Asked Questions about Prepper Spray

I’m ready, I’m ready

As we all know, Israel has accused Hamas of using tunnels to plan, exercise, and conduct attacks on targets inside of Israel. These reports were initially dismissed by Hamas–and then quickly confirmed to be true.

As of this writing, Israeli forces claim they have discovered nearly 800 shafts leading to tunnels under Hamas’ command. Accordingly, Israeli Defense Forces (IDF) have been deploying various counterinsurgency tactics against these tunnels.

After locating a vast subterranean network of tunnels beneath Shifa Hospital in the Gaza Strip, the IDF launched a search-and-destroy campaign, hoping to locate munitions and alleged chemical weapons.

While Hamas has now owned up to building these tunnels, they insist they were not used to hide militants inside of civilian infrastructure. This claim comes amongst various reports that Hamas has been hiding behind civilian targets, especially medical centers, to carry out counteroffensive attacks.

While it’s hard to get a straight answer out of any reports, the IDF insists these tunnels were indeed located amongst civilian targets to deter attacks.

National security advisor Jake Sullivan gave an interview on “Face the Nation '' in October, stating:

“They’re putting rockets and other terrorist infrastructure in civilian areas. That creates an added burden of the Israeli Defense Forces… That’s true of striking from the air. It is true of going in on the ground, and this is something that we talk about with the Israelis on a daily basis. ” 

Of course, working to neutralize these tunnels is no easy task for the IDF. Israel has reported that they’ve uncovered hundreds of kilometers of secret tunnels, bunkers, and access shafts throughout Palestinian strongholds.

While counterinsurgency efforts above ground have continued to be brutal and caused substantial collateral damage, the IDF has been working to surgically dismantle Hamas’ network of underground passageways.

So how has the IDF been employing new military tactics to locate and destroy Hamas’ munitions, while brainstorming radical new solutions? And what’s in these tunnels anyway?

No need to consult your magic conch shell–read on.

Magic Conch Shell that looks like a grenade from Spongebob

“Don’t go in those tunnels.” (Image courtesy of Nickelodeon via Fandom.net)

The Gaza Metro

Hundreds of miles of booby-trapped tunnels have been colloquially called the “Gaza Metro.” Naturally, the IDF have been wary of conducting direct human counterinsurgency operations out of fear of excessive casualties.

As an Israeli Army officer told Retuers: “We don’t want to go down there. We know that they left us a lot of side-bombs”–referencing improvised explosive devices, a popular military tactic commonly employed by guerilla forces.

U.S. forces in Iraq and Afghanistan are no stranger to IEDs and their effectiveness. Indeed, a total of 52% of U.S casualties in Iraq and 48% of casualties in Afghanistan were attributed to IEDs and VBIEDs.

IEDs are so effective that worldwide between 2010 and 2020, over 171,732 civilians and armed actors were killed by them.

IEDs come in many forms and can be wired to detonate on command from cell phone calls and trip-wires, as well as pressure plates and time-delay fuses. Often buried beneath the ground, or installed behind walls, they await their victims silently–out of sight.

They can be designed to counter personnel with excessive shrapnel–often a sloppy makeshift claymore, crafted to inflict maximum suffering–or with armor-piercing plates affixed to the front of them to penetrate armored vehicles.

A popular method of ensuring mass casualties is to wire multiple IEDs into what is known as a “daisy chain.” Daisy chains are created when multiple IEDs are wired to explode simultaneously, or in a certain order that would disrupt troop movement.

A method employed during the Global War on Terror by insurgent forces was to wire munitions to explode from front to back during a vehicle convoy. Essentially, once the first vehicle in a convoy passed a pressure plate, the IEDs would be activated.

Once the convoy had progressed passed multiple daisy-chained IEDs unknowingly, the first IED would explode at the front of the convoy, forcing the rest of the convoy to stop. Now surrounded by IEDs, the convoy was trapped. As the IEDs detonated from front to back, there would be no way to escape–vehicles impeded by other vehicles in front of and behind them.

This writer was deployed during 2010, and again during 2011. In 2010, in Kuwait, he shipped what seemed like thousands of MRAP (Mine-Resistant Ambush-Protected) vehicles to the AOR.

The following year, in 2011, in Oman, he helped ship even more MRAP vehicle wreckers to help move the remains of exploded armored vehicles. While MRAP vehicles saved many lives, many of them were destroyed by IEDs. To eliminate that many vehicles, there would have been a LOT of IEDs.

Imagine, now, the prospect of entering a dark subterranean labyrinth rife with IEDs–not especially attractive, huh?

Luckily, the IDF has devised a few ingenious–and terrifying–solutions. Suppose we should be happy we’re not on the receiving end of their vengeance.

Time to get to brass-tacks and exploding gel. 

Israeli soldiers inspecting tunnels utilized by Hamas for smuggling weapons in 2004.

Israeli soldiers inspecting tunnels used by Hamas to smuggle weapons, 2004. (Image courtesy of Netflix via Comingsoon.net)

Looking for the light

John Spencer of West Point University’s Modern War Institute said: “They face a city underneath that city, from 15 feet underground to 200 feet, 20-30 stories underground… Nothing that was created for fighting on the surface works… You can’t see down there. You can’t navigate, you can’t shoot. It’s literally the worst place any soldier would ever want to go.”

Note that underground, communications and GPS are often scrambled, if they work at all. These signals find little purchase amongst sprawling tunnels made of stone and earth.

Well, necessity often drives innovation.

Along these lines, the IDF has been employing explosive gel and robots to counter Hamas’ network of tunnels. While the formulation of this gel has not been widely disseminated, Israeli engineers have simply said: “The gel spreads out and explodes whatever they had waiting for us in the tunnel.”

Reports from Gaza state that IDF trucks were positioned outside of tunnel shafts, filled with the explosive gel. Soldiers then poured the gel from trucks into the shafts, allowing time for the gel to find its way into every nook and cranny of the network.

Once the gel is properly dispensed, engineers then detonate the gel, collapsing the tunnels. Reports state several tons of gel is required per every few hundred meters of tunnel.

So far, the IDF says this method has been more effective than other military tactics, such as bulldozing above-ground entrances to the tunnels, as well as aerial surveillance drones being utilized to map out and detect the tunnels.

Autonomous robots have been deployed to map out tunnels, scout terrain, and provide surveillance for ground troops. Resembling those weird dog MIT robots that went viral a few years ago, MARBLE (Multi-agent Autonomy with Radar-Based Localization for Exploration) robots are equipped with better stability and a suite of sensory electronics.

Thankfully, these robots have proven themselves highly effective and efficient in mapping out Hamas’ tunnels. The same can’t really be said for a six-letter acronym consisting of nine words total.

Snark aside, such robots do present one substantial problem: They’re really easy to shoot, as they don’t have any armor, and they’re pretty slow. To be specific, over the rough terrain and pitfalls of the hastily constructed tunnels, these robots can traverse about one kilometer an hour.

Bear in mind that tunnels were built to withstand bombings, with certain parts heavily fortified to resist penetrating missiles. It also cannot be understated how massive the Gaza Metro is, with certain sections nearly 200 ft. deep.

Of course, that doesn’t take into account stopping for obstructions, and also planning/executing a new route around them. Given the treacherous environment of the tunnels, however, robots are still an excellent choice when considering counterinsurgency solutions.

Robots are expendable, they can be replaced, and they don’t ask for free college or make cringe TikToks about having firewatch on weekends.

Naturally, these tactics have been highly successful in locating and destroying enemy munitions, as well as helping to map out the extent of these tunnels. Such intel may be essential in uncovering future targets of attacks, and reveal the extent of Hamas’ ability to plan and coordinate operations.

If you’ve been thinking, “Why hasn’t the IDF just taken some big rocks, and moved them over the entrances?” It’s not that the IDF hasn’t considered something similar, it’s just a bit different than most may have suspected.

Enter the sponge bomb. 

An artist's depiction of the possible appearance of the Sponge Bomb.

An artist’s rendition of what the Sponge Bomb may look like. (Image courtesy of unknown artist, via Reddit)

“Ravioli, ravioli. Give me the formuoli!”

Developed to be a hand-held weapon, the sponge bomb is a secret formula of expanding foam.

Despite best efforts, we do not have the “secret formuloli” for the sponge bomb, but preliminary speculation would suggest it is similar to commercial urethane foam.

You’ve undoubtedly come in contact with a similar foam if you’ve ever floundered around in your attic for Christmas decorations, or created floats for a parade. That former example is a bit rare, but that doesn’t make it illegitimate.

Once the foam is hardened, it can be shaped and formed to facilitate repairs or creative endeavors.

Commercial urethane foam is used commonly in construction to seal off holes in structures, and to provide insulation in buildings. You may have come in contact with this hardening foam during your Black Friday shopping sprees, as it’s also commonly used to ship delicate products.

Just like how urethane foam gently supported your new stand mixer–or giant TV that you bought with your girlfriend’s grandpa on an impulsive shopping spree that you now regret because, we mean, seriously, it barely fits on your wall–it could also support Israel’s counterinsurgency campaign.

The sponge bomb weapons are allegedly capable of being deployed inside of tunnels to effectively deprive occupants of oxygen. The liquid emulsion within the hand-held device is hazardous to work with, as some Israeli soldiers have reported losing their eyesight from handling the compound.

This lends credence to the theory of this weapon consisting of a urethane formulation, as it also carries severe hazards to mucous membranes–especially the eyes.

Allegedly, the weapon could be tossed against a wall or lobbed into a cavity where IDF personnel intend to seal off access. How the weapon would then be detonated or activated is up for debate. What we know for sure though, is that this type of foam does a wonderful job of seeping into every and any possible crevice.

With such penetration, once hardened, this type of foam would be an effective seal against any surface it was applied to. If this space was entirely filled with foam, oxygen would quickly become a rare commodity.

Note that hypoxia, or lack of oxygen, is a common danger in confined spaces such as tunnels. With oxygen already a rare resource underground, lowering it to any concentration lower than 20.9% would be a simple feat.

And even if direct suffocation doesn’t occur, hypoxia is still terribly debilitating, with symptoms ranging from impaired judgment and lack of coordination, to fatigue and collapse.

This writer once encountered a nitrogen-gas leak inside of an enclosed space. Nitrogen gas is inert, meaning that it will displace oxygen. Thankfully, he was able to evacuate quickly, but not before feeling the effects of hypoxia: namely, disorientation and behavior changes, as he quickly forgot why he was inside of the confined space–and quickly egressed.

Before we go any further, It’s important to note that this is not a confirmed weapon. The IDF has not commented or confirmed the existence or use of such a weapon. Skeptics claim this is because the IDF is worried that deploying munitions like the sponge bomb could cause unintended casualties.

Until the IDF can map out the entirety of Hamas’ tunnel system, they cannot be sure that sealing off parts of the tunnel infrastructure would cause disruptions to hostage reclamation, as there are scattered reports that hostages are being detained inside of these tunnels.

Since we can’t confirm the existence of such weapons, let’s take a quick moment to discuss some examples of foam weapons that have been confirmed to exist. 


A man with a sticky foam weapon on his body.

A sticky foam weapon. (Image courtesy of Wired.com)

Sticky situations

In Somalia, 1999, U.S. Marines fielded devices that were capable of shooting streams of sticky foam to immobilize insurgents. These types of weapons had the capability to dispense a glue-like substance that would envelop a combatant, and disable them.

One issue with this “non-lethal” weapon–that nearly all non-lethal weapons share–is that it’s hard to aim and it spreads quickly. While glue and foam applied to the torso of an insurgent would certainly disable them, if it was sprayed into their face… well now it’s a lethal weapon.

Such weapons would also be effective at disabling weapons systems such as automatic machine guns, drones, artillery, and even vehicles. A deployed foam or glue could quickly clog the air intake of a vehicle, or obscure vision from a tank view-sight.

Army Col. John B. Alexander, perhaps best known as the partial inspiration for the book “The Men Who Stare at Goats”, was reportedly responsible for spearheading technologies that would make non-lethal glue and foam weapons viable. His ideas included developing a vehicle arrest system that could absorb the kinetic energy of a moving target, and bring it to a stop.

In 2009, the U.S. Army awarded a contract to Adherent Technologies to develop a non-lethal crowd deterrent. This weapon was to be used to stop vehicles while avoiding bodily injury. It is unknown whether or not this capability was fully developed or ever implemented.

However, the Department of Energy’s National Nuclear Security Administration uses trucks filled with sticky immobilizing foam to protect itself from attack or accidents. We will probably never know if these vehicles can deploy this foam to deter hijackers, but given their James-Bondesque nature… it’s kinda cool to think about?

Speaking of thinking about James Bond scenarios, what does MIRA Safety offer in the way of defense against a threat like sticky non-lethal hardening foams? 

The "goo gun" that sprayed sticky foam demonstrated by Jeff McDowell.

No thank you. (Image courtesy of Cabinet Magazine)

MIRA Safety, Is The Safety Solution for You and Meeeeee

So here’s the rub. What can you do to protect yourself from something like a non-lethal hardening foam?

Let’s first define the threats it presents:

Restriction of movement
Irritation to sensitive areas
Secondary exposure

We want to avoid getting it on our skin, we want to avoid breathing in the fumes it presents and protect our eyes, and we want to protect against secondary exposure like nerve agents.

It’s important to note that gas mask filters are only effective if there is an ambient 17% oxygen remaining in the air. So ideally, we want to avoid confined areas when escaping or countering a hardening agent such as thing one.

If trapped in a confined space which has then been sealed off with expanding foam, you may find yourself with limited options to keep yourself in the fight.

Remember that the best defense is often a solid offense. Before you find yourself backed into a corner, or a confined space, make sure you shape the battlefield to your advantage–move in the open, behind cover, and stay protected. 

MIRA Safety CM-7M Military Gas Mask
The MIRA Safety CM-7M Military Gas Mask is your number one choice when facing an opposing force attempting to force you into a confined space. Push back with a tapered design specially designed for the cheek weld on rifles and other long weapons. The recessed binocular visor allows for aiming with night vision optics and red dot systems. If the best defense is a good offense–stay strapped.
MIRA Safety HAZ-SUIT Protective CBRN HAZMAT Suit
The MIRA Safety HAZ-SUIT Protective CBRN HAZMAT Suit will keep your skin protected against a myriad of chemical and biological threats. If you’re fighting back against an aerosol or liquid based agent, you’ll want your hide covered by the premium protection our HAZ-suit offers. The puncture resistant fabric offers superior and uncommon protection against rips, tears, and other physical damage. 
MIRA Safety CBRN Gas Mask Filter NBC-77 SOF–40mm Thread
Last but not least, the MIRA Safety CBRN Gas Mask Filter NBC-77 SOF–40mm Thread is your choice of filter against the unknown. Offering protection against ALL known CBRN agents, and a wide variety of harmful and toxic chemicals and substances, you’ll breathe easy as its unique filter construction protects you from solvent vapors like polyurethane. Whether using it to seal your attic against the upcoming winter, or countering nerve agents, you’ll be set up for success. 
Spray Foam Soundproofing

Don’t let this be you. (Image courtesy of Anderson Insulation)

Wrapping Up

The world of survivalism requires innovation and creative thinking. As such, MIRA Safety offers a wide variety of safety products for professionals and every-day enthusiasts.

Of course, we don’t sell oxygen tanks, and we can’t say you can breathe through a filter that’s been clogged heavily with a sealing foam.

With that said, we offer products that can keep you out of any sticky situations you might find yourself in. Often, products are presented as THE solution to countering threats. In the case of hardening foams and oxygen deprivation, MIRA Safety can give you the tools to build a solution–avoiding finding yourself in that situation in the first place.

Remember: avoid, evade, counter–in that order.

Let MIRA Safety be your guide to emerging and developing threats facing the world we live in. If we don’t offer a direct solution to a threat, we offer the tools and knowledge to counter it.

Stay savvy, and stay safe.


Frequently Asked Questions

What is counterinsurgency?
What munitions did Israel find in Hamas’ tunnels?
What military tactics did tunnels allow Hamas to conduct?
What exactly is an improvised explosive device (IED)
How do authorities typically detect and handle IEDs in urban areas?
What are common signs or indicators that someone might come across an IED?
How can you spot potential IED threats in everyday situations?
Can technology help in detecting or preventing IED attacks?
What should someone do if they suspect they've come across an IED or a suspicious item?
Are IEDs only a military concern, or should civilians worry too?