The death of Kim Jong Nam, the half-brother of North Korean dictator Kim Jong Un, in the Kuala Lampur Airport, was apparently due to the use of the deadly nerve agent VX.
According to a report by the London Telegraph, the Malaysian police do not believe that anyone else is at risk, but teams are sweeping the airport to decontaminate areas where the suspected killer may have been. The Associated Press reported that four individuals who Malaysian police are interested in have fled the country, including a North Korean diplomat and a worker with the regime's state-run airline.
An M55 rocket being disassembled at Umatilla Chemical Depot. This was one delivery system for VX, a very deadly nerve agent. (US Army photo)
VX was first developed by British scientists in the 1950s as an insecticide. The deadliness of the agent caught everyone by surprise, and it soon found its way into American arsenals. The telegraph notes that those who are hit may feel one of two opposite initial reactions: Giddiness or nausea. Shortly afterwards come the convulsions as the nervous system shuts down.
A victim's one chance for survival when exposed to VX is a rapid administration of atropine. That drug counters the effect by blocking nerve receptors that VX seeks to overwhelm. The Telegraph notes that Western intelligence agencies believe that North Korea has about 5,000 tons of this nerve agent.
DOD graphic showing the effects of various chemical agents, including VX. (DOD graphic)
The United States had VX in stock, with one delivery system being the BLU-80 "Bigeye" chemical bomb, according to Designation-Systems.net. After the 1996 Chemical Weapons Convention, the United States discarded all of its VX – and other chemical weapons.
(YouTube screen grab from John Mason)
The nerve agent was used as a plot point in the 1990s action movie "The Rock," which starred Nicolas Cage and Sean Connery. The details surrounding it were not accurate technically.