A picture of Syria's President Bashar al-Assad on the facade of the police academy in Aleppo. In March, rebels said they captured the academy after days of fighting. (Mahmoud Hassano / Courtesy Reuters)

In a recent article for Foreign Affairs, the political scientist John Mueller wrote that we should not care about Syrian President Bashar al-Assad’s reported use of chemical weapons. His case hinges on the argument that Iraqi leader Saddam Hussein’s unleashing of massive amounts of mustard gas and nerve agents on unprotected civilians during the Iran-Iraq War in the 1980s had few consequences. Yet there is ample evidence that the weapons had severe immediate and long-term effects on those exposed to them. And the international community’s indifference to Saddam’s use of the poisons led the Iraqi regime to increasingly rely on them. In turn, Iraq’s unchecked chemical weapons program gave Iran the impetus to pursue a chemical weapons program of its own.

There is an international norm against the use of such inhuman weapons for a reason: they are profoundly devastating. As the Syrian conflict intensifies, chemical weapons could make the civil war more violent and destabilizing. And simply turning a blind eye to Assad’s testing of American red lines will only complicate the endgame in Syria.

MARTYR CITY

On March 16, 1988, Saddam launched a devastating chemical attack on the Kurdish city of Halabja. Iran called for a UN investigation to determine the death toll, but Iraq denied inspectors access to the city. An authoritative study by Human Rights Watch lists various estimates of the casualties -- some are as low as 600, but most range between 3,500 and 6,000. A Red Cross official estimated that attacks between March 16 and March 18 left some 5,000 civilian casualties, excluding Iranian soldiers. (Even today, gas trapped in basements continues to kill.)

Days after the strike, journalists from the BBC and other news agencies entered the town and documented “ghastly scenes of bodies strewn along Halabja's streets, families locked in an embrace of death, lifeless children, doll-like with blackened mouths, eyes, and nails.” These visual impressions, and biological samples taken from victims moved to Iranian hospitals, documented just how deadly chemical warfare really is.

The horrors of Halabja, and those of many other Iraqi towns, amount to more than what Mueller describes as “episodes.” Because the international community declined to speak out about Halabja and Saddam’s sprawling chemical weapons program, Saddam continued to use chemical weapons to quell the Kurdish insurgency throughout the Iran-Iraq war. And his strategy worked: the population and local Kurdish militias so feared chemical attacks that the insurgency crumbled. Twenty-five years later, the chemical weapons campaign against Kurdish towns and villages remains a national trauma. In fact, the Kurdish regional government in Iraq considers it part of a genocide.

STAKES IN SYRIA

Several countries now believe that the Assad regime has used chemical weapons in Syria over the past few months. The details of the incidents are difficult to ascertain, since the Assad regime hasn’t allowed UN inspectors to investigate. Yet footage of surviving patients from more recent attacks and biological samples have since been smuggled out of Syria and seem to confirm those countries’ fears.

These incidents have been described by American officials as small-scale attacks. According to the Syrian American Medical Society, a strike in Aleppo on March 19 injured about 300 people and killed 30. The injuries appeared consistent with the use of nerve gas. The operation might have been intentionally limited in scope: the regime needs to develop its basic skills in deploying chemical weapons. It might also have wanted to test the reaction of the international community before launching a larger campaign.

As was the case with Saddam, failing to respond to Assad’s first reported use of chemical weapons may well encourage him to try it again, and with greater scope and efficiency. It seems that the Assad regime already has the means to carry out larger attacks. Israeli intelligence officials suspect that Syria has between 15 and 20 large chemical weapons sites near its airfields. If those sites come into play, the Syrian conflict could enter a new stage of destruction.

For one, the death counts could increase dramatically. The deadliest individual incident in the Syrian civil war, a battle that opposition figures claim killed 566 in late April this year, was reportedly waged over several days. Saddam’s chemical weapons killed thousands of civilians on a single day. Chemical weapons do have the capacity to kill on a considerably larger scale than Assad’s conventional weaponry has done so far in Syria.

And then there will be those who don’t die; the lingering effects of exposure to chemical weapons (such as mustard gas) are debilitating. They damage the nervous system and can lead to chronic respiratory problems. The exposed population is at greater risk of developing other serious diseases as well. Large-scale use of poisonous chemicals can contaminate houses, water supplies, and agricultural soil. These long-term effects will add difficulty to what will already be a challenging part of the reconciliation process once the war is over.

Moreover, Assad’s widespread use of chemical weapons would complicate the efforts of outside powers to stem the killing in Syria. In the past, Syria has indicated that the purpose of its chemical weapons program is to deter Israel. Last year, a spokesperson for the Syrian Foreign Ministry said that the regime would consider using chemical weapons to counter foreign aggression. Following Israeli strikes this past week, which targeted a site reportedly associated with the development of chemical weapons, Syrian officials indicated that they will now consider all options. If left to his own devices, Assad, like Saddam, may come to rely even more on his chemical arsenal as a deterrent against foreign actors.

Given the size of Syria’s chemical establishment, and the chaotic civil war, neighboring states are increasingly concerned that chemical weapons could be transferred to (or taken by) radical groups operating on Syrian territory. The Syrian regime has already accused rebels of using chemical weapons. If the regime loses control over sites associated with its large chemical weapons complex, the risk of radical actors accessing such weapons makes the conflict even more destabilizing.

For now, a red line has been crossed without consequences. The United States has few appealing ways to respond, which makes arguments that simply dismiss the damage that chemical weapons can do all the more attractive. Even if the Obama administration is not prepared to do anything, however, it would be a mistake for the world to simply ignore Assad's behavior. Chemical weapons can kill thousands in a single day, their use becomes a national trauma, and their debilitating effects linger for decades. In Iran and Iraq, survivors of chemical warfare still suffer. Undermining the norm against the use of such weapons in conflict is dangerous, both in the short and long term. Any discussion about the Syrian conflict, and how the international community should proceed, should start from that point.