North Korea’s progress toward developing a nuclear arsenal capable of targeting opponents as far away as the United States has long been a subject of concern for American defense officials.  Few weapons in history can illicit such a sense of dread and foreboding, but with the potential for conflict on the Korean Peninsula reaching new highs, there are other weapons that deserve similar levels of concern: North Korea’s chemical and biological stockpiles.

The assassination of Kim Jong-un’s half-brother, and early favorite to lead the nation, Kim Jong Nam, not only provided us with insight into the mind of North Korea’s Supreme Leader, but served as a reminder of North Korea’s secretive chemical and biological weapons programs.  VX, the chemical identified as the weapon used to murder Kim Jong Nam, is widely considered to be difficult enough to produce to require state-level backing of the laboratory that made it, and multiple North Korean operatives were implicated in the assassination.  Of course, North Korea still publicly rejects the notion that their government was involved, meanwhile everyone tied to the plot with North Korean roots managed to escape Malaysia and prosecution.

The use of VX to kill Kim Jong Nam by North Korea, while publicly refuted, could be seen as a message intended for the world at large.  Prior to this incident, there was no hard evidence to support the idea that Kim’s regime has been developing and stockpiling these forms of weapons, considered illegal by the international community.  Like the radioactive isotope, polonium 210, that killed Alexander Litvinenko tied his murder to the Kremlin in a way Putin was able to deny, the use of VX to kill Kim Jong Un’s brother was also meant as a very public, and very worrisome, statement.

“North Korea has deliberately built its NBC [nuclear, biological, chemical] infrastructures in extreme secrecy; undertaken camouflage, concealment and deception operations . . . and dispersed NBC facilities around the country,” Joseph S. Bermudez Jr., a prominent expert on North Korean weapons systems, wrote in a joint report released by Johns Hopkins School of Advanced International Studies and the U.S. Korea Institute last month.