Russian spy attack nerve agent was rare, dangerous and sophistic – KTVQ.com | Q2 | Continuous …

… the height of the Cold War in the 1980s, as a means of countering US chemical weapons defenses. Its existence remained secret until the mid-nineties, when information regarding its production was revealed as part of a deliberate leak by disgruntled Soviet scientist and whistle-blower Vil Mirzayanov.