"Syria has produced, stored, and weaponized chemical agents, but it remains dependent on foreign suppliers for chemical precursors. The regime of President Bashar al Asad possesses stocks of nerve (sarin, VX) and blister (mustard gas) agents, possibly weaponized into bombs, shells, and missiles. The government also has associated production facilities. Chemical weapons and their agents can deteriorate depending on age and quality; little is known from open sources about the current condition of the stockpile. Syria continues to attempt to procure new supplies of chemical weapons precursors, which are dual-use, through front companies in third countries. Most countries that have had chemical weapons arsenals in the past have destroyed, or are in the process of destroying, these weapons under the Chemical Weapons Convention. The U.S. intelligence community cites Iran, North Korea, and Syria as having active chemical weapons programs. The Syrian government acceded to the Chemical Weapons Convention on September 14, 2013. This convention requires its member states to eliminate all of their chemical weapon stocks, munitions, precursor chemicals, and related production and storage facilities."
CRS Report for Congress, R42848