 Complete the following phrase:  Some countries known to possess VX are the United States, the United Kingdom, Russia, North Korea, and Syria. A Sudanese pharmaceutical facility, the Al-Shifa pharmaceutical factory, was bombed by the U.S. in 1998 acting on information that it produced VX and that the origin of the agent was associated with both Iraq and Al Qaeda. The U.S. had obtained soil samples identified as containing O-ethyl hydrogen methylphosphonothioate EMPTA, a chemical used in the production of VX which may also have commercial applications. Chemical weapons experts later suggested that the widely used fonofos organophosphate insecticide could have been mistaken for EMPTA. Cuba obtained VX during the 1980s and deployed it during its 