Yes, poison gas is still used today, despite a near-universal international ban. The Chemical Weapons Convention, which 193 states have committed to, prohibits the development, production, and use of chemical weapons. Every declared stockpile from signatory nations has been verifiably destroyed, with the United States completing destruction of its own arsenal on July 7, 2023. Yet confirmed attacks have occurred repeatedly in the last decade, primarily in Syria, and new incidents continue to surface in other conflicts.
The Syrian War: A Decade of Confirmed Attacks
Syria represents the most extensive documented use of chemical weapons in the 21st century. The Organisation for the Prohibition of Chemical Weapons (OPCW) has confirmed multiple attacks using both nerve agents and industrial chemicals weaponized against civilians and combatants. In April 2017, OPCW investigators found “incontrovertible” evidence that sarin was used in an attack on Khan Sheikhoun. Sarin was also confirmed in a separate attack near Ltamenah in March 2017.
Chlorine gas, an industrial chemical that becomes a weapon when deliberately deployed against people, was used repeatedly. OPCW investigators confirmed chlorine attacks in Saraqib in February 2018, where a military helicopter dropped at least one cylinder that ruptured and released chlorine over a large area, affecting multiple named individuals. A 2019 OPCW report concluded that chlorine was likely used as a weapon in Douma in April 2018, one of the most widely reported incidents of the war. Earlier attacks in Kafr Zeita in 2016 were also traced to industrial chlorine cylinders repurposed as chemical weapons.
These findings are significant because chlorine is not a banned substance on its own. It is a common industrial chemical used in water treatment and manufacturing. The Chemical Weapons Convention does not restrict its production or trade, but it explicitly prohibits using any toxic chemical as a weapon. This loophole in materials, if not in law, makes chlorine appealing to those willing to violate the treaty: it is cheap, widely available, and difficult to trace back to a weapons program.
Nerve Agents in Targeted Assassinations
Chemical weapons have also appeared outside of active war zones, used not on battlefields but in targeted poisonings. In March 2018, two Russian intelligence officers applied a Novichok nerve agent called A234 to the door handle of former Russian spy Sergei Skripal’s home in Salisbury, England. Both Skripal and his daughter Yulia fell seriously ill. In August 2020, Russian opposition leader Alexei Navalny collapsed after drinking tea at a Siberian airport, later confirmed to have been poisoned with a Novichok agent as well.
Novichok agents are sometimes called “fourth generation” nerve agents. They were developed in secret during the Soviet era, and their structures remained classified until a Russian chemist disclosed some details in 1992. Their chemical structure is distinct from older nerve agents. The portion of the molecule that binds to the body’s enzymes is significantly larger than in any other known nerve agent, which may contribute to their extreme potency. Following the Salisbury attack, parties to the Chemical Weapons Convention voted in October 2019 to add Novichoks to the treaty’s list of controlled toxic chemicals, bringing them under formal international oversight for the first time.
Chemical Agents in the Ukraine Conflict
The war in Ukraine has produced its own chemical weapons allegations. Both Russia and Ukraine have accused each other of using toxic chemicals on the battlefield. In November 2024, the OPCW published a report on one such incident: an alleged attack on September 20, 2024, near the village of Illinka in Ukraine’s Dnipropetrovsk region. OPCW-designated laboratories independently confirmed that grenade and soil samples collected from a trench contained CS, a riot control agent commonly known as tear gas.
This matters because the Chemical Weapons Convention draws a clear line: riot control agents like tear gas are legal for domestic law enforcement (crowd control, for instance) but are explicitly prohibited as a method of warfare. Dropping tear gas into a trench on a battlefield crosses that legal threshold, turning a common police tool into a chemical weapon under international law.
How Nerve Agents Kill
Understanding why these weapons are banned starts with understanding what they do to the body. Nerve agents like sarin, VX, and Novichok all attack the same biological target: an enzyme that clears a signaling molecule from the gaps between nerve cells. Normally, when a nerve fires, this signaling molecule is released, triggers the next nerve or muscle, and is then quickly broken down so the signal stops. Nerve agents lock onto the enzyme that does the cleanup, permanently disabling it.
The result is that signals never stop. Muscles keep firing. Pupils constrict to pinpoints. The body produces excessive saliva and sweat. Muscles twitch uncontrollably, then weaken. In severe exposure, the person loses control of their respiratory muscles and suffocates. Without treatment, death from a significant nerve agent exposure can occur within minutes. The biological damage from these agents is measured in days to reverse, even with medical intervention, because the enzyme remains disabled long after the chemical itself has dispersed.
Choking agents like chlorine work differently. They attack the lining of the airways and lungs directly, causing fluid buildup that essentially drowns the victim from the inside. At lower concentrations, chlorine causes burning of the eyes, throat, and skin. At higher concentrations delivered in an enclosed space, it can be fatal.
Who Remains Outside the Treaty
As of the end of 2024, four countries have not ratified or joined the Chemical Weapons Convention: Israel (which signed but never ratified), Egypt, North Korea, and South Sudan. The remaining 192 member states are bound by the treaty’s terms, and 100% of the chemical weapons stockpiles declared by those nations have been verifiably destroyed.
But destruction of declared stockpiles does not eliminate the threat. Syria was a member of the convention when its forces carried out confirmed chemical attacks. The challenge is not just about stockpiles sitting in warehouses. Many dangerous chemicals, particularly chlorine and other industrial compounds, are produced globally for legitimate purposes. Converting them into weapons requires no sophisticated infrastructure, just the willingness to use them against people.
Evolving Delivery Methods
The way chemical agents reach their targets has changed. In Syria, helicopters dropped industrial gas cylinders onto populated areas. But the rapid spread of drone technology has raised concerns about new delivery possibilities. Small commercially available drones can carry payloads and could theoretically be fitted with aerosol dispersal systems to release chemical agents over a targeted area. This technology is inexpensive, widely available, and lowers the barrier for both state militaries and non-state groups to deliver toxic chemicals with precision and at a distance. The accessibility of drones grants even small armed groups the ability to project chemical threats far beyond what was previously possible with mortars or improvised munitions.
The Gap Between Law and Reality
The international legal framework against chemical weapons is, on paper, one of the most successful arms control achievements in history. Nearly every nation on earth has signed on, and every declared stockpile has been destroyed. In practice, the record since 2012 tells a different story. Sarin has been dropped on Syrian towns. Novichok has been smeared on doorknobs in England and slipped into drinks in Siberia. Tear gas has been confirmed in battlefield trenches in Ukraine. The weapons are banned. They are still used. The gap between the two defines the current state of chemical warfare: rare compared to conventional weapons, but far from eliminated.