The Syrian civil war has developed a well-deserved reputation as a humanitarian catastrophe. Recent events in Syria continue to bear this grim reality out. On April 4, a chemical attack struck the northern Syrian village of Khan Shaykhun, approximately 50 kilometers to the south of Idlib city. The victims from Khan Shaykhun showed the unmistakable signs of nerve agent poisoning, and the death toll soon reached approximately 80 people. After attributing the attack to the Syrian Arab Air Force, President Donald Trump ordered limited strikes against the airfield from which the attack was said to have originated.

What followed in the aftermath was a back and forth between Western governments and the Assad regime and its supporters. U.S. officials presented evidence of the flight path of the strike aircraft involved in the attack, which showed that they departed from the same airbase later hit with U.S. cruise missiles. Unnamed officials also reported that they had intelligence that confirmed Syrian military officials planned the attack. The Organization for the Prohibition of Chemical Weapons (OPCW), for its part, confirmed victims were exposed to sarin, a lethal but fast-dissipating chemical weapon. Also, the French government released its own intelligence assesment placing the blame for the attack on the Assad government.

Regime supporters, however, have stubbornly attempted to cast doubt on the idea that the Syrian government was responsible, or even that a chemical attack took place at all. Al Masdar News, a pro-regime news organization, initially announced that the attack was the result of Syrian aircraft bombing a rebel rocket production facility. Syrian President Bashar al Assad, for his part, asserted that the chemical attack was staged, a charge soon echoed by Russian President Vladimir Putin.

Former MIT professor Ted Postol, famous for his work studying the effectiveness of Patriot missile intercepts during the Gulf War, asserted that the chemical attack was more likely the result of a rebel false flag attack. Postol is by now an established contrarian on chemical weapons matters in Syria, having frequently pushed conspiracy theories that hold rebels responsible for chemical weapons usage. After the Ghouta chemical weapons attack on August 21, 2013, for instance, Postol asserted that it was impossible for the Syrian government to have been responsible, and he enlisted the help of pro-Assad conspiracy theorist and Infowars contributor Maram Susli to help prove it.

Leaving aside the numerous technical errors and logical inconsistencies in Postol’s analysis, such denialism touches upon an enduring skepticism that the Syrian government would ever even use chemical weapons. This assumption is apparently based in the idea that the regime lacks sufficient motive to launch such attacks. Yet chemical weapons used by governments fighting against insurgencies or hybrid threats have been sufficiently common to reveal the hollowness of Postol’s arguments. Three key historical case studies — Italy in Ethiopia, Spain in Morocco, and Iraq in both Iran and Kurdistan — show that the Khan Shaykhun attack shares many of the same characteristics as the usage of chemical weapons in those conflicts.

Negative Population Control, Positive Population Control

David Galula, a 1960s French counterinsurgency expert and veteran of the Algerian War, echoed Mao Tse Tung when he argued that insurgents move among the population as fish move through the water. Imagine your counterinsurgent is a fisherman, who seeks to catch those fish. To do so, the must separate those fish from the water. A fisherman can accomplish this by the use of a rod or a net. But using those tools is challenging, and is certainly not guaranteed to work. So, as Frank Kitson argues, “it may be necessary to do something to the water which will force the fish into a position where it may be caught.” In this conception, the task of capturing the fish is made easier by lowering the water level.

In U.S. counterinsurgency doctrine, the “water level” is drained by working with a host nation to protect the civilian population in an attempt to win its support, while also using a targeted killing tools such as special operations forces and drone strikes to thin out the insurgent population as it becomes exposed. Another school of thought seeks to deny the insurgent safe haven by targeting the civilian population in which they hide. In doing so, the counterinsurgent forces the civilian population to flee or die in place, thus denying the insurgent both its support base and its camouflage. This allows the counterinsurgent to critically weaken the social base of a population upon which the insurgency depends for everything from food and shelter to intelligence and recruits. And as Paul Staniland argues, the more robust the social base supporting an insurgency, the more adaptable the insurgent group. Violence against these social bases weakens the insurgent group’s ability to successfully adapt to government attacks.

If one seeks to target that civilian population, chemical weapons are well-suited to the mission. Though modern militaries can protect themselves easily using passive defenses such as chemical protective equipment, the logistical challenge of extending such protection to a larger civilian population is cost-prohibitive for even the most advanced economies. This is more challenging in less-developed regions, where such defenses are priced out of reach for even the insurgent fighters themselves. David Galula, for his part, recommended that the French Army in Algeria turn a forest serving as an insurgent safe haven into a chemical weapons testing range for this very reason, but his commanders rejected this suggestion.

The Italian invasion of Ethiopia presents us with a useful case study. In an attempt to expand his colonial holdings, Italian fascist dictator Benito Mussolini invaded Ethiopia in October 1935, an invasion that included heavy use of chemical weapons, in this case sulfur mustard, a weapon that causes painful chemical blisters, blindness, and lung damage. Though it started as a state-on-state conflict, the collapse of the Emperor of Ethiopia, Haile Selassie’s Christmas Offensive quickly led the conflict to resemble the present-day war in Syria, with one well-equipped side holding a near-monopoly on offensive action, while a poorly equipped force attempted to slow its adversary’s advance as they lived in and around the civilian population.

The Italians recognized that their chemical stockpile gave them an advantage from the outset. In preparing for the invasion of Ethiopia, Italian planners assumed that an “absolute superiority of gas” would be essential to their offensive operations. Upon entering Ethiopia, the Italian Air Force engaged in a campaign of civilian targeting. On March 19, 1936, for instance, Italian aircraft bombed towns, villages, hospitals, fields, water sources, and livestock with sulfur mustard. Water sources contaminated by sulfur mustard would cause lethal intestinal damage, as the chemical agent burned the lining of the digestive tract, forcing civilians to abandon their communities upon discovering their only water sources had been rendered undrinkable. Italian field commanders specifically ordered that hospitals specifically be targeted with chemical weapons. Benito Mussolini even asked Field Marshal Badoglio, the Italian commander, if he wanted bacterial weapons — an offer Badoglio declined.

The Spanish fought the Rif War against a rebellious confederation of Arab tribes in the mountains of Morocco from 1920 to 1926. In this war, they too extensively used sulfur mustard against insurgent-supporting civilian populations. In May 1924, for instance, field commanders ordered a “highly intense and continuous campaign of bombing and destroying the enemy’s cattle and crops…[using] other bombs.” In this case, “other” was the clandestine way the Spanish military referred to its chemical weapons stockpiles in Morocco. Such bombing efforts had the desired effect: French officials in Tangiers reported a flood of women and children, many suffering from chemical wounds.

Perhaps the most notorious example of this from recent memory, however, was the Iraqi chemical attack on the Kurdish town of Halabja in March 1988, as part of the Anfal Campaign at the end of the Iran-Iraq War. This attack struck the small Kurdish village with both conventional and chemical bombs, including sarin, just as Assad’s forces would nearly 30 years later. The first attacks used normal high-explosive bombs, which both drove civilians into basement shelters as well as broke open the villages windows and doors. These initials attacks were then followed up with chemical munitions, which quickly filled the basement shelters and killed their occupants.

Such brutality was intentional. The attacks were intended to break the back of the Kurdish peshmerga militia by depopulating its support. Commenting on the matter at the time, Iraqi Gen. Ali Hassan al-Majid bragged that he would “kill [all the Kurds] with chemical weapons.” The chemical bombardment of Halabja had its desired effect, with a stream of surviving civilians abandoning the town and fleeing to nearby Iran. This use of chemical weapons, moreover, had another added benefit: driving away civilians and insurgents who had become numb to the effects of conventional weapons.

Stage Management and International Messaging

Despite these clear examples, the Syrian government and its supports have stuck to a common refrain in their denials: Syria wouldn’t dare risk the international cost of using chemical weapons. Others have pointed out that this chemical attack followed signaling from the U.S. State Department that indicated that Assad could remain in power. But even if this wasn’t the case, the three states mentioned above also risked international consequences for their chemical weapons use, and yet used chemical weapons anyway. They did so because they felt they could stage-manage their chemical weapons use in such a way to forestall a reaction.

In the case of the Italians in Ethiopia, despite the extensive reliance of chemical weapons, their usage was also tempered by a desire to avoid international intervention. The movement of chemical weapons into the theater took place under strict secrecy. Once in theater, the release of chemical weapons was centrally directed by Mussolini specifically to avoid repercussions at the League of Nations. In 1935, for instance, Mussolini denied a request on the part of his forces in Ethiopia to use chemical weapons to attack the towns of Dire Dawa and Harar, explicitly out of fear that such an attack would provoke an international outcry.

In Morocco, the Spanish also exercised elaborate secrecy. Chemical weapons were brought into theater marked only as “X Bombs,” and any reference to chemical weapons in official communications in anything except code was expressly forbidden. The dropping of chemical munitions was kept so secret that accurate expenditure figures were not maintained. Spanish authorities went so far as to label civilian casualties appearing in hospitals suffering from mustard burns as victims of typhoid. These denial and deception measures were so successful that many of the documents that historians are forced to rely upon are autobiographies from the participants and coded messages in the Spanish archives.

In Iraq, Saddam Hussein was extremely cautious in his use of chemical weapons from the outset, despite the fact that he required outside support to maintain his war against Iran. Chemical strikes launched by Iraq had to be carried out only with Saddam’s express permission . Indeed, it was only until Saddam was confident that such an outside reaction would not be forthcoming that he finally gave his ground commanders more latitude in deciding when and where chemical weapons should be used. The control over chemical weapons previously had been so tightly controlled that Saddam had to visit the frontlines in person to confirm the order to his commanders.

In these ways, too, we can also see the value in the taboo against chemical weapons use. In these cases, the revulsion these weapons create are such that even in the cases where states use chemical weapons against civilians they are forced to limit the scale and intensity of these attacks so as to avoid international outrage. In the case of Iraq, moreover, it was the comparatively muted response on the part of the international community that emboldened Saddam to relax the restrictions governing when and where chemical weapons could be used.

Tu Quoque

The Assad regime and its supporters have predictably claimed that it was the rebels who used chemical weapons. This line of argument has also been a common response by states that use chemical weapons.

Take the Iran-Iraq War: Though this was a tradition war between nation-states, the introduction of chemical weapons followed a script that looks unsurprisingly similar to that of Syria. It was the consistent position of Iraq that it had never used chemical weapons and that Iran was responsible for bringing these terrifying weapons into the conflict. The Iranian government was quick to use troops wounded by chemical weapons as a way to garner international sympathy and to attempt to diplomatically isolate Baghdad. Western journalists would be taken to the front to be shown unexploded chemical rounds (often with unintended consequences). These efforts resulted in diplomatic hearings at the United Nations aimed at imposing sanctions upon Iraq.

In making this case, the Iraqi government would parade out its troops who had been wounded by chemical weapons. But these Iraqis were actually accidentally exposed to chemical weapons fired by their own forces. Plumes of chemical agent would float back across the lines and into formations of unprepared Iraqi troops. Iraqi aircraft and artillery would accidentally bombard friendly positions with chemical weapons. Iraqi troops would assault Iranian positions that had been struck with more persistent chemical weapons (such as tabun and cyclosarin) without leaving sufficient time for that agent to clear.

This mirrors the 2013 chemical attack by Assad’s forces in Ghouta. In the aftermath of the attack, evidence emerged that Hizballah, a staunch Assad ally taking part in the fighting, had not been warned that such an attack was imminent, which left Hezzballah forces exposed to sarin. The level of irritation Hizballah showed in the wake of the attack underlines this mistake, a senior Hizballah commanders openly criticized their Syrian allies in the press.

Conclusion

Pro-regime voices have taken an incredulous tone in the wake of the Khan Shaykhun chemical weapons attack. In their telling, the very idea that the Syrian regime would use chemical weapons against an insurgent force is absurd. Yet Ethiopia, Morocco, and Iraq indicate that the Syrian government’s use of chemical weapons fits well-established trends. Chemical weapons are well-suited to targeting civilian populations, especially when doing so can deny their irregular adversaries the ability to support themselves in the field. When governments opt to use chemical weapons in this way, then, they also do many of the same things the Syrian regime has done. They use chemical weapons against the very infrastructure needed for civilian life support. They employ chemical weapons sparingly so as to avoid international outcry. And when that outcry does take place, they accuse the victims of being the aggressors.

The deliberate stonewalling by Assad supporters denies that the regime engages in any form of civilian targeting. Yet this line of argument ironically leads these figures to miss a more nuanced view of what may have happened in Ghouta and Khan Shaykhun — one that would not absolve Assad, but might reveal him to be slightly less monstrous, at least as far as chemical weapons are concerned. Again, observers can look back to the case studies above for analogues. In the case of the first chemical weapons use by the Italians in Ethiopia, ample evidence suggests that one of the local ground commanders exceeded his remit. Mussolini’s directives that centralized the authority to use these weapons came directly after the first chemical attacks in Ethiopia. In the case of Iraq, Saddam Hussein’s debriefers, such as the Central Intelligence Agency’s John Nixon, recently suggested that the use of chemical weapons against Halabja may not have been ordered by the dictator and may have occurred on Ali Hassan al-Majid’s own initiative. The popular image of Iraq under Saddam was one in which individual commanders were completely paralyzed with fear, only acting on explicit instructions from Baghdad. Yet as mentioned earlier, by the time the Halabja attacks took place,Saddam had become convinced that the muted international response to his previous uses of chemical weapons meant that he had a free hand to use chemical weapons on the battlefield. As such, he had then explicitly empowered his commanders to use chemical weapons on their own authority. As Nixon suggests, Saddam was actually infuriated that such an attack took place, not because of the humanitarian cost, but instead because it caused him a black eye internationally.

In the end, for the most ardent of regime apologists, it doesn’t matter what happened at Khan Shaykhun last month. But for honest and serious students of military history, the incident offers further insight into the dynamics of how chemical weapons are used in irregular warfare. Understanding this not only leads to a better understanding of both chemical weapons and counterinsurgency, but also allows us to see past the hollow and predictable excuses of autocrats and their apologists.

Luke O’Brien is a U.S. Army officer assigned to Aberdeen Proving Ground and is currently a Countering Weapons of Mass Destruction Graduate Fellow at National Defense University. He is also a member of the Military Writers Guild. His views are his own, and do not represent those of the Department of Defense, National Defense University, or the U.S. Army. He can be found on Twitter as @luke_j_obrien.

Image: Adam Jones, CC