Even if the international community is able to take control of Syria's chemical weapons, the U.S. experience in destroying its own stockpiles suggests eliminating those from Damascus could be a complicated, lengthy and even risky endeavor.

The U.S. has been systemically destroying its chemical weapons since the 1970s, but the job of eliminating nerve gas and other agents will take another decade because of the hazards of the disposal process, U.S. officials and weapons experts said.

"Safety is overengineered into these things and that takes time," said Greg Mahall of the U.S. Army Chemical Materials Activity, which has oversight over U.S. stores of chemical weapons and for the majority of the destruction of chemical weapons.

The U.S. used chemical weapons against German forces during World War I, and made the Chemical Warfare Service a permanent part of the Army in 1920.

The Army ramped up production of chemical weapons in the ensuing decades to use for retaliation in case of use by Axis forces in World War II or the Soviet Union during the Cold War, but never deployed them, according to the Army Historical Foundation.