Not Crossing a Red Line: Chlorine Barrel Bombs In Context


The use of chlorine improvised explosive devices against Syrian civilians, as a weapon of war, seems to be a subject of heated commentary. Although the United States successfully led an effort to destroy Syria’s existing chemical warfare agents and associated production facilities, Assad’s field commanders are now allegedly using chlorine tanks inside of “barrel bombs” to kill and panic the Syrian people. The State Department has expressed its dismay at this behavior, stating that, if verified, such a violation would have consequences. The Organization for the Prohibition of Chemical Weapons, the implementing body of the Chemical Weapons Convention (CWC), believes that chlorine was “systematically and repeatedly” used as a weapon in northern Syria, without blaming the government directly for those actions. However, as the victims have tended to be Syrian civilians and not government forces, and the mode of delivery has been by helicopter, the list of probable suspects is pretty short.

As a result of four years of civil war, Syrian deaths have climbed to more than 200,000. Of those, perhaps one percent has been caused by chemical weapons. Nonetheless, in 2013, the Obama administration felt compelled to act against Syria when its forces used several rockets filled with sarin nerve agent to kill almost 1,500 people, viewing this violation of international norms as something that required immediate redress. Sabers were dutifully rattled, and Washington gathered forces for an attack. The Syrian government admitted to producing chemical weapons and acceded to the terms of the Chemical Weapons Convention that same year, forestalling a U.S. military reaction. Disposal of its chemical warfare agents and dismantlement of its production facilities quickly followed. So given this fact, why are these cases of chlorine attacks happening? More importantly, is U.S. Ambassador to the United Nations Samantha Powers right when she said, “the use of chlorine weapons [is] no less evil than that of chemical weapons?” The short answer is emphatically no.

Let’s start with a few basics. Chlorine is not named in the Chemical Weapons Convention as an inspectable chemical because it is so prevalent in industry as a basic precursor for other materials, used on the order of tens of millions of tons every year. Water treatment plants across the globe depend on chlorine to provide clean, drinkable water. It is used in the production of most pharmaceutical drugs. People across the world swim in water treated with chlorine. But it can also be toxic and even deadly. When chlorine was used by military forces during World War I, it was as an act of improvisation, and it worked – for a short while. Once troops were provided simple gas masks, they could protect themselves when they saw the telltale greenish-yellow fog slowly floating toward them. Chlorine was not a very effective chemical weapon, and that’s why no nation after 1917 ever used it as a munition on the battlefield.

The Syrian government did not declare its stocks of chlorine gas as a chemical weapon when it acceded to the CWC in 2013. And it did not need to. Still, the wording of the treaty’s first article makes it clear that signatories are not to use chemical weapons or engage in any military preparations to use chemical weapons. The second article defines a chemical weapon as any munition or device specifically designed to cause death or harm through the properties of a toxic chemical. Clearly, the design and use of a chlorine barrel bomb fits that description.

To a layperson, it might seem clear that the Syrian government has broken faith as a signatory of this treaty. However, this is an area best left to diplomats, since the evidence presented publicly has been circumstantial. The Organization for the Prohibition of Chemical Weapons has fact-finding missions in Syria but has still been very careful not to accuse the Syrian government of orchestrating the chlorine attacks. Despite videos of victims of gas attacks, the U.S. government has not acted against Syria. The Chemical Weapons Convention is an agreement between nation-states. Syria has not attacked any nation-states with chemical weapons. At best, this is a UN Security Council issue, and as the UN Security Council addresses this, there are some countries that do not believe that the United Nations should sanction a nation for dealing harshly with cases of civil unrest – even to this extent.

Resolution 2209, which passed the UN Security Council on March 6, 2015, states “that those individuals responsible for the use of chemicals as weapons, including chlorine or any other toxic chemical, must be held accountable” and that it will remain “actively seized of the matter.” It does not, as reporter Josh Rogin states in his article, call on the Syrian regime to cease dropping chlorine barrel bombs on civilians. It reminds Syria of its obligations under the Chemical Weapons Convention but does not accuse them of any perfidy. So that’s where the UN Security Council stands. This is the realm of diplomacy.

Given these facts, what is Assad’s angle? Why would the Syrian military use chlorine barrel bombs in its attacks against the Syrian insurgents, given close international scrutiny and the relative lack of effectiveness of chlorine as a casualty-causer? There could be a number of reasons. First, it could be that Assad wants to interpret the Convention language more loosely. He’s given up the production, storage, and use of militarily designed chemical warfare agents. He could blame his field commanders for using chlorine in improvised chemical weapons under their own discretion. Certainly Assad doesn’t need these improvised chemical weapons to retain power – his conventional military forces and its actions are doing the overwhelming majority of killing and taking ground. At best, the use of chlorine barrel bombs represents an attempt to intimidate and terrorize the populace. At least, it represents Assad thumbing his nose at the West, asserting his dominance as a state leader to control events within his borders.

Chlorine is a minor league hazard compared to nerve agents, despite the liberal and careless use of the broad term “chemical weapons” seen in the press. The U.S. military is very busy supporting Iraqi military forces against the Islamic State, which coincidently is an enemy of Assad’s government. So given Syria’s compliance with the dismantling of its formal chemical weapons program, does it make sense for Western nations to use military forces to deter Assad’s forces from using chlorine gas against the populace when (a) that action could aid the Islamic State in retaining or gaining ground in Syria; (b) the chlorine attacks have not significantly helped Assad nor disproportionally killed civilians; and (c) there is no international consensus – even among America’s closest allies – on how to deal with the direction of Assad’s civil war?

We will still hear outcries from the arms control community and the Responsibility to Protect crowd that we need to “do something.” And here’s my concern. Many diplomats and arms control specialists see no difference between the small-scale use of improvised chemical munitions and heavy use of Scud ballistic missiles with VX-filled warheads. They see no difference in threat between Iran and North Korea’s nuclear weapons programs and China and Russia’s nuclear weapons stockpiles. This is a very black and white Cold War view, one that removes the nuances from discussions on unconventional weapons and does not help us address contemporary security challenges. The fact is, nonproliferation regimes are not well-suited to address chemical terrorism or the state use of chemical weapons during internal civil unrest.

Ridiculous news titles such as “The Spector of Chemical Warfare Returns to the Middle East” unnecessarily elevate these cases of improvised chemical weapons to the status of chemical weapons’ use in the Iran-Iraq conflict in the 1980s, Saddam Hussein’s use of nerve gas against his own population, or Yemen’s civil war in the 1960s. This comparison isn’t accurate or helpful. Egypt caused perhaps 3,000 chemical casualties in Yemeni villages over a period of years, while Iran’s military suffered more than 50,000 casualties from Iraqi chemical weapons. Assad is a violent and ruthless leader, and he intends to retain power by all means possible. But he is the leader of a nation-state that is also in a very volatile part of the world, and there are rules for dealing with national leaders. These incidents of using improvised chemical munitions are unfortunate, but in the end, what Assad is doing with his conventional forces is the real war crime.

When people hear the name of the city Halabjah, they think of the thousands of Kurds killed by Saddam Hussein’s military, which also used chemical weapons against unprotected civilians. They overly fixate on the “horrors” of chemical warfare, not recognizing perhaps that the real crime was the organized and systematic use of conventional military forces to cause mass casualties among noncombatants. Similarly, we should not get so focused on the occasional use of chlorine barrel bombs that we overlook the real tragedy – the thousands of Syrians being killed in this brutal conflict.


Al Mauroni is the Director of the U.S. Air Force Center for Unconventional Weapons Studies. The opinions, conclusions, and recommendations expressed or implied within are those of the author and do not necessarily reflect the views of the Air University, U.S. Air Force, or Department of Defense.


Photo credit: Freedom House