Seoul, South Korea: Was it a poorly executed assassination or did North Korea want to showcase its stockpile of banned chemical weapons?
The use of the highly toxic VX warfare agent to kill the estranged half brother of North Korea's leader has raised questions about Pyongyang's real motives in one of the strangest killings the world has seen.
Some say North Korea, in allegedly bringing a U.N.-classified weapon of mass destruction to kill a man at a busy international airport, intended to show the world what it can do with chemical weapons, which are easily forgotten amid concerns about the country's advancing nuclear missile technologies.
But other experts believe it's unlikely that North Korea wanted VX to be discovered. There's no reason for Pyongyang to risk taking another hit when it's already under heavy international sanctions over its nuclear program. It's also doubtful that the country would be suddenly willing to showcase its chemical weapons as a deterrent when it has never acknowledged their existence, the experts say.
For Pyongyang, killing Kim Jong Nam, who might have been seen as a potential threat to leader Kim Jong Un, would have been the clear priority that made any other consideration secondary, said Koh Yu-hwan, a North Korea expert at Seoul's Dongguk University.
"They probably picked the deadliest chemical at their disposal because they absolutely didn't want to fail at killing Kim Jong Nam," Koh said. "The fallout of using VX at an international airport could turn out to be significant for the country, but I doubt that the North Koreans thoroughly thought this through."
North Korea has denied involvement in the Feb. 13 attack on Kim Jong Nam at Kuala Lumpur's airport, and also refused to confirm that it was Kim who died. Saying that one of its nationals died from a "heart stroke," North Korea has strongly criticized the investigation by Malaysia, which has been one of its few legitimate diplomatic partners, and made repeated demands for Kim's body.
The overwhelming presumption that North Korea's government organized a hit job on Kim only strengthened after Malaysian police announced they found VX on his eyes and face. Analysts say it's almost certain that the highly powerful nerve agent, which scientists say is capable of killing 500 people through skin exposure with an amount weighing as much as just two pennies, would have been sourced from North Korea's state laboratories as its materials are tightly controlled internationally and hard to obtain.
South Korea's military believes North Korea has one of the world's largest stockpiles of chemical weapons with up to 5,000 tons that include sarin, mustard, tabun and hydrogen cyanide, in addition to V-type nerve agents.
If North Korea really did use VX to assassinate Kim, it would indicate a new level of sophistication in its handling of chemical weapons. The North Koreans probably needed to conduct many tests before figuring out the precise amount of VX that would kill Kim Jong Nam without harming the assailants or anyone else nearby in one of the world's busiest airports.
While some Western analysts have argued through the media that North Korea might have used Kim's assassination to draw attention to its chemical weapons, most South Korean experts doubt it.
North Korea, which has been pursuing nuclear weapons as an ultimate deterrent, has little to gain by highlighting its chemical weapons, which would only bring harsher punitive measures and put further pressure on the United States to relist the country as a state sponsor of terrorism, analysts say.
"North Korea was already under immense pressure over its efforts to develop nuclear weapons and intercontinental ballistic missiles, and also its human rights issues. Things will get even more complicated for Pyongyang if its chemical weapons issues are thrown into the mix," said Chang Yong Seok, an analyst at Seoul National University's Institute for Peace and Unification Studies.
Perhaps North Korea expected that its use of VX would go undetected because only a tiny amount would have been needed to kill Kim, experts say.
Or maybe using VX might have been a logical choice for North Korea because it relied on two lightly trained foreign women to do the job. North Korea would have been reluctant to directly use its own operatives when it had no plans to acknowledge its involvement. A less powerful chemical, including those needing injection devices or other equipment, would have increased the possibility of the women failing to kill Kim or would require larger dosses that might have put more lives at risk.
It's still unclear how the two women handled the VX without contaminating themselves and others, including travelers and medical workers who handled Kim's body.
Some analysts say that North Korea probably produced VX in the form of a binary agent, where two chemicals that aren't separately deadly become a nerve agent when mixed together.
But a South Korean military researcher, who didn't want to be named because he wasn't authorized to talk to reporters, has doubts. While it can be made as a binary agent, VX doesn't synthesize easily, so wiping a person's face separately with two of its component chemicals may not be a surefire way to kill him, said the researcher.
What's more likely is that the North Koreans who allegedly organized the assassination coated the women's hands with protective chemicals before putting VX on them, he said. Aside from the two suspects, police have also arrested a North Korean who worked at a Malaysian company and are seeking seven more North Koreans who are believed to have been involved in Kim's death, including an embassy official and an airline employee.
"The security camera footage shows one of the women heading to the bathroom to wash her hands after attacking Kim. If she touched VX with her bare hands, she wouldn't have had the time to do even that," said the researcher.
