The Biological Shadow War: Dr. Glenn Cross on Covert Threats

Editorial disclosure: this article is based primarily on Dr. Glenn Cross's essay "Biological Weapons in the 'Shadow War,'" published by War on the Rocks on November 9, 2021. Dr. Glenn Cross, the U.S. Intelligence Community, War on the Rocks, the UK Defense Science and Technology Laboratory, the FBI, and NIOSH are not affiliated with CBRNMASKS.COM and have not endorsed the company or its products. Analysis, preparedness conclusions, and product recommendations are by David Magen alone.

Imagine a senior official leaving a private meeting in perfect health. By evening, he feels feverish. By morning, he is in intensive care. The doctors see an aggressive infection, a toxin, or an organ failure they cannot immediately explain. There was no gunshot, no bomb, no suspicious package, and no declaration of war. The first question is medical: what is happening to him? The second question arrives much later: who wanted this to happen? That delay is the weapon.

The Biological Shadow War: Former U.S. WMD Intelligence Official Explains the Threat Nobody Sees Coming

A conventional assassination announces violence. A biological operation can borrow the appearance of nature — resembling food poisoning, an ordinary infection, an unexplained medical collapse, or a laboratory accident. The attacker may be gone before the victim develops symptoms, and the political decision to retaliate may remain trapped behind scientific uncertainty. This is the biological threat described by Dr. Glenn Cross, former Deputy National Intelligence Officer for Weapons of Mass Destruction and Proliferation, who was responsible for biological-weapons analysis on the U.S. National Intelligence Council, and later founded Crossbow Analytics.

This analysis is best read alongside al-Qaeda's long search for WMD and RAND on civilian biodefense and vital workers. Together, they connect the threat picture with its operational and civilian-preparedness implications.

The Apocalypse Is Not the Most Likely Scenario

Cross begins with a conclusion that runs against almost every Hollywood image of biological warfare: he does not believe the most realistic modern threat is a state releasing a contagious super-pathogen in the hope of killing millions. Large biological attacks are difficult to control, difficult to deliver reliably, and potentially dangerous to the country that launches them. Advanced conventional weapons can destroy military targets more predictably and with fewer political complications. The quieter use of biology is different.

In Cross's assessment, biological weapons retain value for intelligence services and special-operations forces precisely because they can be small, targeted, and deniable. The objective may be one dissident, one commander, one airfield, one port, or one critical piece of infrastructure — not an entire population. The adversary does not need to defeat a national army with disease. It may need only to remove a person who holds unique knowledge, delay aircraft from taking off, disrupt a naval facility before a conflict, or create confusion inside a command structure at the moment decisions are most urgent.

A Weapon Designed to Look Like Something Else

Cross argues that the dual-use character of biological research has repeatedly defeated intelligence services. Western governments failed to understand the true scale of the Soviet biological-weapons program, Iraq's program before the Gulf War, and smaller programs in Rhodesia, South Africa, and Chile. By the time a program begins large-scale weaponization and military testing, it becomes easier to observe. The earlier and more covert stages are much harder to distinguish from civilian science.

The same ambiguity remains after use. An unexplained illness does not arrive with a national flag. Medical laboratories must identify the agent. Investigators must reconstruct exposure. Intelligence agencies must decide whether the event was natural, accidental, or deliberate. A state considering a covert operation understands this burden — it does not have to make attribution impossible. It may only need to make attribution slow.

The Umbrella on Waterloo Bridge

History already contains a model for the kind of attack Cross fears. In September 1978, Bulgarian dissident Georgi Markov became suddenly ill after feeling a sharp pain in his leg near Waterloo Bridge in London. He died several days later. UK Defense Science and Technology Laboratory scientists identified ricin delivered through a tiny pellet injected into his thigh — an assassination remembered through the image of a modified umbrella.

Markov was not attacked with an aerosol cloud. No public respirator would have saved him from a pellet placed beneath the skin. That fact is important because it reveals both the attraction and the complexity of biological and toxin weapons. "Biological protection" is not one product — protection depends entirely on how the agent reaches the body. A toxin injected through the skin is different from an airborne pathogen. A contaminated meal is different from an aerosol released through ventilation. A respirator may be highly relevant in one scenario and almost irrelevant in another. The commercial value of respiratory protection begins with telling that truth.

Why Authoritarian Regimes May Prefer the Shadow

Cross argues that targeted biological use is especially compatible with regime security. Authoritarian governments often fear defectors, journalists, scientists, opposition leaders, and former insiders who possess information the state cannot retrieve. A conventional assassination risks creating an obvious martyr and a clear international crime scene. An unexplained disease or toxin exposure may initially look like misfortune. Even when attribution eventually points toward the state, time has already worked in the attacker's favor: evidence may have degraded, witnesses may not understand what they saw, the agent may be unfamiliar, and the victim may have visited multiple locations before becoming ill.

When the Target Is a Port, Airfield, or Command Center

Cross's argument extends beyond assassination. Special-operations forces could theoretically use biological agents or toxins against fixed strategic targets shortly before a larger conflict — leadership, command-and-control facilities, military airfields, and naval ports as the kinds of locations that could be vulnerable to covert disruption. The objective would not necessarily be to kill everyone at the facility: a cluster of unexplained illness can be enough to stop work, isolate personnel, close a building, or force commanders to treat an entire site as contaminated. A bomb leaves a crater that engineers can inspect. A suspected biological release can make every air duct, cup, desk, uniform, and person part of the investigation.

This is where Cross's analysis becomes commercially relevant to organizations far beyond the military: ports, airports, diplomatic facilities, data centers, hospitals, and private-security teams all face the same uncomfortable question — what happens during the hours between suspicion and identification?

The Letter That Changed How America Opened Its Mail

The 2001 anthrax letters demonstrated how a small biological event can create national consequences. Five people were killed and seventeen became ill. The FBI's Amerithrax investigation consumed hundreds of thousands of investigative hours and became one of the most complex investigations in the Bureau's history. The quantity of material was small compared with a military biological arsenal. The effect was not. Mail facilities were disrupted, government offices were treated as potential contamination scenes, and laboratories had to connect microscopic evidence with envelopes, postal routes, and human behavior. The attack showed that a biological weapon does not need to spread through an entire city to make an entire country feel exposed.

The First Warning May Be Medical, Not Military

A shadow biological attack reverses the normal emergency sequence. The first people to understand that something is wrong may be emergency physicians, infection-control nurses, or laboratory technicians. The initial patients may not be connected to one another. Security personnel may continue working inside the exposure area because no one has yet declared it dangerous. By the time the incident acquires a name, the exposure window may have closed. That is why organizational preparedness cannot begin with a shopping list — it must begin with decisions: who has authority to isolate an area, who can shut down ventilation, who communicates with medical services, where protective equipment is stored, and which employees are expected to use it.

Where Respiratory Protection Fits — and Where It Does Not

A full-face respirator is not protection against "biological weapons" as a single category. It is protection against specified airborne hazards when the correct mask, filter, fit, and conditions come together. In an aerosol scenario, a properly fitted full-face mask can reduce inhalation of biological particles and protect the eyes. A powered air-purifying respirator can move filtered air into a hood, reducing breathing resistance and avoiding the need for the same tight facial seal required by a conventional mask. NIOSH notes that PAPRs draw air from the surrounding environment — they do not create oxygen and must be used with the correct components and filters for the hazard.

The limits are equally important. A respirator cannot stop an injected toxin. It cannot make contaminated food safe. It cannot prevent exposure through an open wound. It cannot diagnose infection or replace an antidote, antibiotic, vaccine, or medical treatment. The mask is a tool for the airborne route — not a force field against every form of biological attack.

Building a Practical Family Respiratory-Protection Kit

Adults: the Israeli 4A1 Black Diamond Simplex — panoramic visor, 40mm threaded filter connection, hydration tube, sealed Israeli filter. For bearded users, the Israeli Sapphire PAPR hood — loose-fitting hood that avoids the facial-hair seal problem.

Children, ages 2–8: the MAMTAK / Quartz child PAPR hood — transparent protective hood with ONYX blower, delivering powered filtered airflow for young children who cannot seal a conventional adult mask.

Infants and toddlers, ages 0–2: the Multipro infant protection system — designed for infants and toddlers who cannot use a standard gas mask.

Children, ages 8–14: the Israeli 10A1 child gas mask.

Filters: CBRNMASKS.COM offers Israeli PA-12 and M80 Type 80 40mm CBRN/NBC filters. Filter selection must match the documented hazard and manufacturer specification.

Explore the Israeli CBRN Family Bundle or the complete range at CBRNMASKS.COM.

Protect Your Family

4A1 for adults, Sapphire for beards, MAMTAK / Quartz for ages 2–8, Multipro for infants. Sealed 40mm filters for every mask — also available as 2-pack, 3-pack, or 4-pack for multi-person households. Israeli CBRN Family Bundle for the complete household. CBRNMASKS.COM — Israeli civil-defense equipment, in service since 2009.

Primary Sources

Analysis and preparedness conclusions by David Magen — former Combat Investigation Officer, Doctrine and Training Division, IDF Operations Directorate; former Staff Officer, National Emergency Authority, continuity planning for local authorities, Haifa region. Founder of CBRNMASKS.COM since 2009. Dr. Glenn Cross, the U.S. Intelligence Community, War on the Rocks, Dstl, and the FBI are not affiliated with CBRNMASKS.COM and have not endorsed the company or its products.

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