In the 15 years that the accord banning the use or possession of chemical weapons has been in force, 78 percent of the world’s declared stores has been destroyed, and the rest are scheduled for demolition. With the arrival in Syria this week of an international team to inspect this regime’s program, there is hope that another significant stockpile will be demobilized.

Syria was pressed to accept the weapons ban in order to ensure that the Aug. 21 massacre in which some 1,400 people died in a Damascus suburb is not repeated. But what can be done to reduce the possibility of another such atrocity elsewhere?

One goal should be to improve the control of chemicals that can be used to make weapons.

After Syria officially joins the convention Oct. 14 – as part of the U.S.-Russia plan to decommission its chemical weapons program – the country will have to fully account for all the chemical arms it’s ever had, as well as detail any assistance or imports of chemical agents or precursors it has received from abroad. Finding out who may have aided Syria in gathering its stockpile will help plug holes in international enforcement of the convention.

Even if Syria received no help or if the facts can’t be determined, it is only prudent for all countries to improve controls on chemicals that can be used for weapons. Given the enormous volume of trade that national inspectors must police, it will always be difficult to stop proliferators who are determined to skirt the rules. But governments can work harder to prevent unintentional violations.