"Known binary agents include the following: GB binary (sarin, GB2): DF is located in 1 canister, while OPA is in a second canister. The isopropyl amine binds to the hydrogen fluoride generated during the chemical reaction. After deployment of the weapon, the 2 canisters rupture and the chemical mixture produces GB."
The US destroyed it's chemical weapons stockpile in the 1990's and 2000's. After the fall of the Soviet Union, there's no use case for chemical weapons and precision weapons are more profitable.
"Known binary agents include the following: GB binary (sarin, GB2): DF is located in 1 canister, while OPA is in a second canister. The isopropyl amine binds to the hydrogen fluoride generated during the chemical reaction. After deployment of the weapon, the 2 canisters rupture and the chemical mixture produces GB."