Chemical weapons are once again a global threat

How to prevent a future gas war

For a number of reasons, experts suspect that chemical weapons will be used more frequently again in the future. Interstate wars are becoming less frequent, while civil wars and rebellions have greatly increased since the turn of the millennium. On the one hand, this increases the risk that existing chemical warfare agents will fall into the hands of non-state groups.

On the other hand, important factors that make chemical warfare agents uninteresting for modern armies are lost in such conflicts. Militias, and usually the armies of unstable countries, do not have the training and firepower required for effective conventional warfare. Their units are less mobile, and they are undertrained and underequipped for effective NBC protection.

At the same time, several factors make it more difficult to monitor the ban laid down in the Chemical Weapons Convention in practice. The Chemical Weapons Convention provides several instruments to prevent states from secretly producing chemical warfare agents. On the one hand, the signatory states are obliged to monitor trade in chemicals and equipment suitable for this purpose. On the other hand, the Organization for the Prohibition of Chemical Weapons (OPCW) inspects facilities that produce or use chemicals necessary for chemical weapons – or are suspected of producing chemical warfare agents.

It is simply impossible to ban all the equipment and materials needed for chemical weapons. Because most of the equipment and chemicals that can be used to produce chemical warfare agents also have legitimate uses. For example, the substance DMMP is the starting material for the production of the nerve toxins sarin and soman – but it is also a common flame retardant. Thiodiglycol, from which mustard gas is made directly, is also used to dye textiles.

However, there are some key elements that can be used to detect potential violations of the ban. You need special reactors and specialized safety and cleaning technology to work safely with the aggressive and highly toxic chemicals. Such specialized industrial plants are fairly easy to trace – as are a number of chemicals that are also or almost exclusively used for the production of chemical warfare agents.

Chemical weapons are becoming increasingly difficult to monitor

That is why it has so far been sufficient to keep an eye on a relatively limited list of substances and devices. In addition, the OPCW carries out inspections to ensure that the requirements of the convention are being complied with. The facilities capable of producing chemical weapons have historically been very large and elaborate, and OPCW experts can recognize them by their specialized facilities for handling aggressive and highly toxic chemicals.

But advances in chemistry and technology are making this type of control increasingly difficult. “Policy positions and structures that have served us well for decades have been challenged in recent years,” wrote Norwegian chemist Leiv K. Sydnes, chair of an international working group assessing the impact of scientific advances on the CWC, in 2018 should, in a comment in Nature.

»We need a new mentality«(Leiv K. Sydnes, University of Bergen)

There are now processes that require less complex installations – or even synthetic routes that do not require controlled chemicals. At the same time, with the economic development of many emerging countries, it is becoming easier and easier to source dual-use products from different countries. “Many lethal components are easy for professional chemists to make if they have access to the materials,” writes Sydnes. He calls for trade in it to be monitored more closely – and chemists to be made aware of the dangers. »We need a new mentality.«

There are now new types of production plants that do not require large, specialized reactors or protection technology. Thanks to more modern processes, hazardous waste and by-products are only produced in small quantities, so that at first glance the factories look like normal chemical plants.

New techniques also facilitate research into new chemical weapons. In March 2022, a working group demonstrated that a machine-learning algorithm can not only find potential new drugs, but also extremely toxic new warfare agents. Industry screening methods could be used, for example, to find substances that are as deadly as sarin but belong to a different class of substances. Such substances could therefore be produced with other, possibly completely innocuous chemicals and equipment.

Modern technology makes detection more difficult – and easier

Last but not least, there is the danger that new warfare agents cannot be identified – and that their use as a terrorist weapon, for example, cannot be proven. If the use of a chemical weapon is suspected, OPCW experts ideally take samples from the scene and – if possible – from blood and tissue of possible victims. The original warfare agent has long since decomposed, but its degradation products can still be detected in the samples.

The analysis concentrates on the primary degradation products, i.e. those substances that are produced directly when the warfare agent decomposes. In the case of sarin, for example, this is the molecule isopropyl methylphosphonate. In order to find these substances, they are enriched from the samples and analyzed using mass spectrometry. The data obtained is compared with that of known warfare agents.

With the help of this method, the nerve gases can not only be reliably distinguished from one another, but also from the many chemically very similar pesticides. However, it becomes more complicated when you come across a previously unknown molecule for which there is no comparable data. An attack with completely new, previously unknown chemical weapons may not be able to be proven with certainty – and thus not punished.

However, other technical advances are helping to control chemical warfare agents. Modern detectors have become smaller and cheaper and analysis methods more sensitive. This means that even the tiniest traces of a substance can be detected in the environment and unknown molecules can be identified. In this way, the use of chemical weapons can possibly be proven, even if the crime scene is only accessible after weeks or months or the warfare agent was previously unknown.

Perhaps the most important change, however, is modern communication technology that documents what is happening in the war zone almost in real time. Satellite photos and cell phone images can provide hard evidence of chemical weapons attacks without waiting for the results of extensive analysis. Above all, however, such recordings distributed over the Internet could cause the same global horror as the consequences of the gas attacks in World War I – and thus rebound on the attacker.