VX attack is N Korea’s deadly signal to enemies

The revelation that Kim Jong Nam was killed with the deadly nerve agent, VX, transforms a brutal piece of internecine political bloodletting into something with far broader implications. Although it denies responsibility, few doubt the North Korean regime is responsible — and is flashing signals to its enemies.

“It is more than just killing someone,” said Patricia Lewis, research director at policy institute Chatham House. “This was a way of sending several messages.”

A 10mg drop of VX the size of a pinhead can kill. Using one of the most toxic substances ever made — a chemical developed primarily as a weapon of mass destruction — is “primarily about spreading fear”, Ms Lewis noted.

VX is one of a family of organophosphate chemicals known as V-agents discovered after the second world war, and refined as a potential weapon by British scientists at Porton Down, the UK’s secret chemical, radiological and biological weapons research centre.

“VX has the same effects as other nerve agents such as sarin, only it is much more potent,” said professor Rod Flower, a pharmacologist and fellow of the Royal Society. “Your nerves talk to each other using chemical signals; at the junctions between them acetylcholinesterase [an enzyme] is released to trigger the next nerve cell.

“What sarin and VX do is that they stop the breakdown of acetylcholine, so it persists between your nerve cells. Effectively it jams all your nerves in the ‘on’ position, causing massive overstimulation of the body.”

[Exposure to VX] produces . . . loss of internal muscle control which then leads to diarrhoea and loss of bladder control

Unlike sarin, which is highly volatile and quickly evaporates, VX is a stable, oil-like substance, without colour or odour, that lingers. Scientists in the 1950s observed that it could last for weeks in the open without degrading. That makes its use in a public space such as an airport terminal particularly reckless. It does not need to be ingested or inhaled to work. Contact with the skin is enough.

Kim Jong Nam’s assassination fits into a long history of baroque political poisonings — from the use of a ricin-tipped umbrella on Blackfriars Bridge in London to kill Bulgarian dissident Georgi Markov in 1978 to the elaborate use of the rare radioactive element polonium to poison Russian Alexander Litvinenko in 2006.

Organophosphates have been used before, too: South Africa’s apartheid regime used clothes laced with the chemicals to kill dozens of political opponents in the 1980s.

But, until now, there has only been one recorded example of VX being used in an assassination, perhaps because it is so dangerous. Aum Shinrikyo, the Japanese doomsday cult responsible for the 1995 Tokyo subway sarin attacks, used VX in 1994 to kill a wayward member.

“It is the most deadly synthetic nerve agent ever made,” said Dr Andrea Sella, professor of inorganic chemistry at University College London. “It was first prepared as a potential insecticide, but its horrendous toxicity precluded its use.”

VX poisoning is a barbaric and visually grotesque way to die. Using the toxin for an assassination implies that stealthiness was not the goal of Kim Jong-Nam’s killers. Quite the opposite.

“[Exposure] produces symptoms of pinpoint pupils, excessive tears being produced by the eyes, and excessive saliva . . . there is loss of internal muscle control which then leads to diarrhoea and loss of bladder control,” said Dr Christopher Morris, senior lecturer in neurotoxicology at Newcastle University. Violent muscle spasms follow, then paralysis, with eventual coma, seizures and respiratory and cardiac arrest, he added.

Officially, North Korea denies possessing any chemical weapons. But independent international non-proliferation experts consider the hermit state to possess the world’s third largest stockpiles.

As tensions on the Korean peninsula have stepped up in recent weeks, the timing and manner of the assassination may be no coincidence.

“Pyongyang has made much of its nuclear deterrence recently, but many question if it could credibly use them in the escalatory manner it says it will,” noted Karl Dewey, chemical, biological, radiological and nuclear analyst at IHS Jane’s publisher. “Chemical weapons have long been regarded as a means of bridging the ‘credibility gap’ between conventional actions and a full strategic [nuclear] attack.”