A little-noticed cable from 2006 described Iranian aid to Syria. Written by a US diplomat, the cable said, “Iran would provide he construction design and equipment to annually produce tens to hundreds of tons of precursors for VX, sarin [both nerve gases] and mustard [gas]. Engineers from Iran’s DIO [Defense Industries Organization] were to visit Syria and survey locations for the plants.”
Syria’s chemical program dares back decades, before the Islamic revolution, and has always been a major concern of Israel. Iran began a chemical weapons program in the 1980s in response to Iraq’s use of chemicals against Iranian troops. Iran used chemical weapons during the war, although it long pretended it did not. However, Iran only used chemicals in five battles and then only after Iraq first fired them against Iranians.
Little is known about the extent of Iran’s chemical weapons program. The US government says little other than that one exists.
Chemical weapons deteriorate fairly rapidly so new production is needed to replace deteriorating stocks.
Near the end of the Iran-Iraq war, the US government discovered a firm in Baltimore, Maryland, was exporting chemical precursors to the Middle East. It was shipping the goods to both Iraq and Iran, making a profit off both sides.