The United States and possibly allies are preparing to launch military strikes against Syria in response to Syrian president Bashar al-Assad’s use of chemical weapons.

The limited, U.S.-led military attacks currently being discussed will force the Assad regime to pay a price for violating the international legal prohibition on chemical-weapons use, as well as President Barack Obama’s red line. They might also reduce Syria’s ability to conduct future chemical attacks. However, an effective effort to reduce the long-term risk of chemical weapons or other WMD use in Syria or elsewhere in the Middle East must also include legal and economic steps to deter further chemical attacks, including by holding individual perpetrators accountable.

President Obama has declared repeatedly that perpetrators “will be held accountable” for the chemical weapons attacks in Syria. Accountability involves requiring the perpetrators to answer for their actions, for example before a criminal tribunal. However, there have been few signs of a concrete plan to hold anyone accountable—or to otherwise impose legal and economic consequences—for the chemical weapons attacks in Syria.

Chemical weapons attacks are an atrocious war crime prohibited by international laws including the 1925 Geneva Protocol, to which Syria is a party. Since World War II, more chemical weapons attacks have occurred in the Middle East than in any other region of the world. In addition to the recent Syrian attacks, Iraq used chemical weapons against Iran in the 1980s, Kurds in 1987-88, and possibly Shiites in 1991; chemical weapons were also used by Egypt against Yemen during the 1960s, by Libya against Chad in 1987, and by al Qaeda in Iraq in 2006 and 2007.

In only one of these cases were individual perpetrators held accountable. Iraq executed Ali Hassan al-Majid, known as “Chemical Ali,” for ordering chemical weapons attacks against the Kurds. In addition, the Netherlands imprisoned a Dutch businessman for supplying some of Saddam’s chemical-weapons ingredients. Perhaps because Chemical Ali and the Dutch supplier being held accountable were the exception rather than the rule, they were insufficient to deter Syria’s chemical-weapons attacks.

Legal and economic measures designed to punish and deter chemical weapons attacks should be aimed at every participant in Syria’s production and use of chemical weapons, including Syria’s president, its generals, its chemical-weapons units’ soldiers, and the foreign suppliers on which Syria’s program still depends.

Holding Syria’s chemical weapons perpetrators personally accountable is complicated, but far from impossible. Syria is not a party to the International Criminal Court (ICC), which has authority to prosecute war crimes including chemical weapons attacks. So long as the Assad regime remains in power and refuses to subject itself to ICC jurisdiction, the ICC can only prosecute chemical weapons use in Syria if the United Nations Security Council refers the case to it. Russia is almost certain to use its Security Council veto power to block such a referral.

However, if the regime falls, a new Syrian government could create its own tribunal, such as the post-Saddam Iraqi tribunal that convicted Chemical Ali, or could grant the ICC jurisdiction to prosecute past international crimes in Syria. Open preparations now for chemical-weapons-use trials by such a future tribunal or by the ICC could help deter additional attacks.

The preparations should be carefully calibrated to deter future attacks rather than stiffen the regime’s resolve to hold on. Regime personnel must be persuaded that they have more to lose if they mount additional attacks.

As the U.S. and other states prepare intelligence reports to justify the use of force, the utility of such information for supporting future prosecutions should also be taken into account. U.S. intelligence on Iraq’s use of chemical weapons against the Kurds contributed to the prosecution and conviction of Chemical Ali by the Iraqi High Tribunal.

The U.S. could also make perpetrators pay a severe economic price for using chemical weapons by imposing new, secondary sanctions on both the Assad regime and specific individuals involved in the chemical attacks. Under a U.S. law enacted in 1991, if a foreign government “has used lethal chemical or biological weapons against its own nationals,” the president must impose various specified primary sanctions. Most of these primary sanctions have already been imposed on Syria for other reasons. But there are relatively few secondary sanctions on the Assad regime or its pillars of support. Secondary sanctions are restrictions—such as denial of access to the U.S. financial system and markets—which are designed to inhibit non-U.S. persons and companies from transacting with a target of primary U.S. sanctions. New secondary sanctions could pressure foreign companies to halt their transactions with the regime and its pillars.

Indeed, the 1991 U.S. law requiring punishment of chemical weapons users does not incorporate the powerful secondary and other sanctions tools developed over the past twenty years. Nor does U.S. law adequately provide accountability for foreign or U.S. suppliers of ingredients used in chemical weapons. For this reason, a lawsuit recently failed in federal court against a Maryland company that allegedly had sold to Iraq the chemicals used to manufacture mustard gas deployed against Kurds at Halabja. The U.S. should adopt new legislation that sets a global standard for punishing chemical or biological weapons perpetrators and their suppliers.

Even though Syria is not a party to the 1993 Chemical Weapons Convention (CWC), the CWC could be leveraged to further punish the regime in Damascus, limit its ability to conduct future chemical attacks, and deter other states from using these weapons. The CWC prohibits parties to it from transferring, to states that are not parties to the CWC, so-called Schedule 1 and Schedule 2 chemicals (which could be used as chemical weapons or to manufacture them but have no or limited commercial applications). CWC parties are allowed, however, to transfer Schedule 3 chemicals, which present some risk of being used in a chemical weapon program but are also produced on a large scale for industrial purposes. According to the Organization for the Prohibition of Chemical Weapons (OPCW), which is charged with implementing the CWC, “The world-wide trade in Schedule 3 chemicals and products containing them is vast, involving such product groups as pesticides, pharmaceuticals, toiletries, resins and plastics, urethanes, adsorbent, antistatic agents, acrylics, preparations used in leather tannery, surfactants, corrosion inhibitors, materials used in gold extraction, vulcanising agents and many more.” The U.S. and other states should push for the OPCW to close this loophole and prohibit the transfer of Schedule 3 chemicals to states such as Syria that have not signed the treaty and have used chemical weapons.

It will take more than a limited military strike to help ensure that the recent chemical weapons attacks are the last in the Middle East, including Syria. Additional steps should be taken now to hold the perpetrators accountable, impose consequences and help prevent future victims of this atrocious crime.

Orde F. Kittrie is a professor of law at Arizona State University and senior fellow at the Foundation for Defense of Democracies. Gregory D. Koblentz is an associate professor and deputy director of the Biodefense Graduate Program at George Mason University.

Image: Flickr/Jeffrey Beall. CC BY-SA 2.0.