Bad Chemistry: A Re-analysis of the Assassination of Kim Jong-un’s Brother

Just over a year ago, Kim Jong-nam, the eldest son of the deceased North Korean leader Kim Jong-il and half-brother of current North Korean leader Kim Jong-un was assassinated in Malaysia’s Kuala Lumpur airport.

Since Kim Jong-un became Supreme Leader in December 2011, more than 300 potential rivals or dissidents have been executed or disappeared by various means including, allegedly, by anti-aircraft battery fire.

However, the Kim Jong-nam murder was particularly gruesome: he was assassinated with a VX chemical nerve agent, a compound which signalled North Korea’s military capability, credibility, and intent as it approaches nuclear status.

Seen from Pyongyang’s perspective, it wasn’t surprising that the regime would seek to eliminate Kim Jong-nam or that the regime would attempt an execution on foreign soil. Some reports indicated Kim Jong-nam was scouted by the Chinese as a potential replacement to his brother, and Pyongyang has attempted several assassination plots abroad in the past. However, the combination of the target, location, and method of the execution portray a dynamic and highly capable North Korea with at least regional operational reach.

At the time it happened – February last year – few open-source analyses commented on the exceptional nature of this assassination. From an operational perspective, the use of VX was wholly unnecessary and carried exceptional risk; given the relatively lax travel and visa requirements between Malaysia and North Korea at the time, Pyongyang’s operatives had numerous conventional options to eliminate Kim Jong-nam, who was frequently on Malaysian soil.

Smuggling a chemical weapon across borders entails unnecessary risks of detection, accidental release, self-contamination or outright failure. So, to rely on this highly complicated assassination scheme in the first place indicates that regime’s scientists, special forces and, most importantly, Kim Jong-Un himself were highly confident of their intelligence and execution capabilities, as well of their unconventional agents and ability to deploy them in the region, and they were also keen for the world at large to know about these capabilities.

Second, this assassination revealed a dramatic technical improvement in North Korea’s offensive chemical capabilities. Previous assessments indicated that North Korea’s chemical stockpiles, while impressive in quantity, were produced and stored as ready-to-use, active-state (unitary) weapons.

For a chemical weapons (CW) state, temporarily stockpiling newly engineered unitary weapons makes sense, during the Cold War, the US and Russia stockpiled new chemical agents as soon as they were developed so they could be immediately called into action.

However, maintaining long-term CW readiness with unitary weapons is expensive and constrains operational flexibility as these weapons degrade on the shelf and are highly dangerous.

On the other hand, binary chemical weapons solve these two major problems. This technology is analogous to separating gunpowder into saltpetre, charcoal, and sulphur. Each component is very stable, simple to handle, but can also be immediately mixed to create a weapon.

For CW, binary components can be safely mass produced and stockpiled, and operators can deploy them with less risk to themselves. Binary components can also be manufactured in dual-use facilities such as agricultural or industrial plants, making their detection more difficult. Seeing these advantages, the US and Russia eventually developed and proliferated binary chemical technologies during the Cold War.

Historically, the US and Russia were assumed to be the only two nations to have successfully developed binary chemical capabilities. However, the assassination of the Kim Jong-nam suggests this is not the case.

Based on video footage taken at that time at Kuala Lumpur’s airport, it would have been unlikely that both assassins escaped unharmed if either had the active agent – a unitary VX nerve agent is so potent that even breathing the fumes is lethal.

In the aftermath of the attack, neither the assassins nor any bystanders fell ill. Instead, it is likely that each woman had an inactive component of VX that combined on Kim Jong-nam’s face to seal his demise. The success of this two-person attack suggests the North may have developed binary CW technical and operational capability.

Binary CW capability could be part of a broader strategic optimisation by North Korea. Apart from the US and Russia, North Korea stockpiles the most CW agents in the world and is estimated to have 2,500–5,000 metric tonnes of CW agents, which serve as a formidable unconventional deterrent.

Preserving these reserves as unitary agents requires enormous input of energy and chemical building blocks that are expensive and subject to export controls. Binary systems could reduce the regime’s dependence on supply chains and import arrangements to continually replenish these reserves, providing greater autonomy and security for the regime. Developing binary capability without external help would certainly be costly in the short term.

However, this short-term investment and strategic shift would allow Pyongyang to maintain a low-cost, long-term CW deterrence in the context of a costly nuclear programme, consistent with sanctions biting into its military-industrial complex.

Aside from the new offensive operational flexibility for the regime, a shift towards binary CW systems may complicate the US and other allies’ defence assessments about the military threat of North Korea. Analysts tracking the regime may have been able to assess capacity and detect a breakout by monitoring the consumption of these controlled goods, but if binary technologies have been more widely adopted, this early warning system and avenue for interdiction may no longer exist.

The signal from Kim is clear: underestimate North Korea at your peril. The regime has actionable rungs on their escalation ladder and first strike capabilities as they finish constructing their ultimate nuclear deterrence.

Combined with the recent UN report showing that North Korea has bartered CW expertise and equipment, it follows that Kim’s regime currently relies in part on maintaining a robust and operational chemical capability for credible deterrence and cash.

Ryan Henrici is a Marshall Scholar at the London School of Hygiene & Tropical Medicine working on infectious disease, emerging technologies, and biosecurity.

The views expressed in this Commentary are the author's, and do not necessarily reflect those of RUSI or any other institution.