A score to settle: Chemical terrorism and its impunity after the war in Syria

Following the end of a bloody 14-year civil war and the fall of Bashar Al Assad's government, the Syrian Arab Republic has been in a highly complex transition phase since December 2024. At the last United Nations General Assembly, Ahmed Al Sharaa, a former fighter with group Al Nusra group , closely linked to Al Qaeda and currently president of the country, spoke on behalf of the new Syrian government, wearing a suit and tie and projecting the image of a diplomatic leader. His appearance marked the Arab nation's return to the international stage, as he was the first Syrian president to set foot in the UN headquarters since 1967. With Syria's return to apparent normality, one wonders what has become of the use of chemical weapons that so marked the years of civil war in Syria.  

One of the most tragic realities of the Syrian civil war has been the repeated allegations of chemical weapons use. Since Syria joined the Chemical Weapons Convention (CWC) in 2013, the Organization for the Prohibition of Chemical Weapons (OPCW) has confirmed the use of toxic chemical agents such as sarin, chlorine, and mustard gas by both the Bashar Al Assad regime and non-state actors, such as terrorist groups. 

The most tragic chemical attack in the Syrian conflict was the attack on the city of Ghouta, in the Damascus region, in August 2013, causing the deaths of numerous civilians, including a large number of children. r government of Al Assad allegedly launched simultaneous attacks on populated areas using a surface-to-surface missile system loaded with sarin gas that struck areas controlled by the civil service examination. This attack marked a turning point, as it was condemned internationally, generating strong political pressure on Syria—mainly from the United States and Russia—to sign and ratify the CAQ and place its chemical arsenal under international control.

Other notable attacks, confirmed by the OPCW, include two attacks attributed to the Islamic State (IS), the attack in Marea on August 21, 2015, and in Umm Hawsh on September 16, 2016. These attacks demonstrated that some terrorist groups have the capacity to acquire chemical agents and use them as weapons of war. Devastating incidents such as these were recurrent throughout the conflict, inflicting massive humanitarian damage in the Syrian Arab Republic, where many of the victims continue to suffer the consequences in the form of respiratory and cardiovascular diseases, psychological disorders, and even newborns with conditions related to exhibition the toxicity of chemical weapons. 

Chemical terrorism: what exactly is it?

Although chemical weapons have typically been used by states, especially during World War I and World War II, their use by non-state actors has become a growing concern. The international community does not have a single, agreed-upon definition of "chemical terrorism." However, this phenomenon can be defined as the intentional use of toxic chemical agents by non-state actors—such as terrorist groups or other individuals acting outside the state—with the goal of causing a large issue casualties and/or generating terror. 

Non-state actors of an extremist or radical nature, whether due to their political or religious orientation, are the most likely to attempt to use a Chemistry weapon. Apocalyptic cults, neo-Nazi groups, and jihadist organizations are possible examples. In this regard, the first time a group used a weapon of mass destruction (WMD) was in 1995, when Aum Shinrikyo, a sect based in Tokyo, released sarin gas on several subway lines in the Japanese capital. This event marked an important milestone and increased international concern by demonstrating the ability of non-state actors to acquire, produce, and use this subject weapon. 

Chemical weapons can be particularly attractive to non-state actors because of their destructive capacity and destabilizing power. The mere threat of using Chemistry weaponscan create a climate of panic and terror, which contributes to achieving the group objectives. Furthermore, as they are considered 'silent' weapons due to their sometimes colorless and odorless nature, it can be difficult to detect their use and therefore prevent it. There are also certain obstacles to the use of these weapons, mainly that they require minimal technical skills and knowledge to manufacture. However, unlike other types of WMDs, chemical weapons are relatively inexpensive and easy to obtain, as many of the toxic chemicals and chemical precursors used have legitimate and commercial uses. In the Syrian context, these factors explain why not only government forces but also terrorist groups resorted to the use of chemical weapons during the conflict.

Some prevention and identification measures

The creation and implementation of measures to combat chemical terrorism is no easy task, given the unpredictability and relative ease of carrying out a chemical attack. Despite these difficulties, there are various mechanisms at the international level to address this threat through prevention and identification measures. 

With regard to prevention, strict control of toxic chemicals that could be used as weapons is crucial. The Organization for the Prohibition of Chemical Weapons (OPCW) is the international body responsible for monitoring compliance with theChemical Weapons Convention(CWC) , ensuring that states ensure the non-proliferation, non-transfer, and destruction of these materials. The OPCW carries out this work through activities such as inspections and monitoring of facilities and attendance programs to ensure the chemicaldisarmament among the signatory states of the CWC. In addition, Resolution 1540 (2004) of the committee Security United Nationsimposes on UN Member States the obligation to establish national measures to prevent the proliferation of WMD, as well as to prohibit and punish any illegal activity by non-state actors, particularly for terrorist purposes. 

With regard to identifying the perpetrators of chemical weapons attacks, certain mechanisms have been put in internship identify those responsible, particularly in the framework the war in Syria. In this context, the OPCW established the mission statement Determination Facts (FFM) in 2014 and the research Identification (IIT) in 2018, the former to determine whether chemical agents were used as weapons during the war, and the latter to identify the perpetrators of such attacks. Noteworthy, for example, are the 21 reports issued by the FFM, covering 74 cases of alleged use of chemical weapons, which conclude that, according to the investigations carried out, subject were used on 20 occasions: in 14 of them, the use of chlorine was detected, in 3 the use of sarin gas, and in another 3 the use of mustard gas. 

In 2016, the UN General Assembly established theInternational,Impartial,andIndependent Mechanism(IIIM) with the goal attend the research prosecution of those responsible for serious crimes under international law committed in Syria since the conflict began in March 2011. It focuses particularly on war crimes, crimes against humanity, and genocide, but it has no powers of prosecution, only attendance. 

Against impunity: good intentions, few results

The international framework establishes certain mechanisms that could be used to prosecute and bring to trial individuals or groups responsible for development, acquisition, use, or financing of chemical weapons.

At the international level, the International Criminal Court (ICC) is the court responsible for prosecuting individuals for particularly serious crimes: genocide, crimes against humanity, war crimes, and crimes of aggression. However, Syria is not a State Party to the Rome Statute, so the ICC cannot prosecute crimes committed in Syria unless the committee refers the matter to the Prosecutor, which is unlikely given Russia's position in the conflict and its veto power in the committee .

At the national level, and in light of this reality, some states have resorted to the principle of universal justice, which allows third states to investigate and prosecute serious international crimes regardless of where they were committed and the nationality of the perpetrator or victim. There have already been multiple cases related to the war in Syria that have been dealt with under this principle, not specifically related to the use of chemical weapons, but rather to war crimes, crimes against humanity, or other human rights subject . 

For the time being, the principle of universal justice has been applied mainly in European countries, including Germany, France, Switzerland, Sweden and the Netherlands, which have been the main drivers in prosecuting those allegedly responsible. These cases have been particularly useful in prosecuting andholdingaccountable foreignfighters who have traveled to Syria to join groups such as the Islamic State or Al Nusra. Recently, the IIIM has collaborated with Swedish and Dutch courts to secure thefirst twoconvictionsofforeignfightersfromISIS against Yazidi victims. This represents a significant step forward in the pursuit of justice for crimes committed in Syria. 

Settle the outstanding account with the victims

After the fall of the Al Assad regime, it is likely that legal proceedings will be easier to initiate. However, cases involving crimes committed by terrorists can be more complicated due to the difficulty of attribution, evidence collection, and capturing those responsible. In addition, the new Syrian transitional regime is led by the then emir of the terrorist organization Hayat Tahrir al-Sham (HTS), which fought against Bashar Al Assad's government during the years of conflict and currently forms the de facto government in Syria.

It is difficult to confirm whether we will ever see those responsible for the atrocities caused by chemical terrorism in Syria held accountable. Despite international efforts and the various mechanisms that fight against these crimes, the current status and the new interim government call everything into question. It is a kind of 'Russian roulette', a status we do not know what to expect: it is the spitting image of a leader willing to collaborate, but with a past that cannot be easily ignored.