Why are states purportedly performing assassinations with chemical and radioactive weapons?
Purportedly the Russian state assassinated Alexander Litvinenko by poisoning with him with:
radioactive polonium-210, believed to have been administered in a cup of tea
Former spy Sergei Skripal and his daughter were poisoned by a military-grade nerve agent of a type developed by Russia, Theresa May has told MPs.
Whilst, North Korea apparently performed a similiar attack.
Kim Jong-nam died after a bizarre encounter at Kuala Lumpur airport in 2017, when two women smeared his face with VX nerve agent.
These chemical and radioactive weapons seem unusual, complicated, and draw attention.
Is there a specific reason these weapons are used, as opposed to a more commonly available weapon?
The reasons given by @zidadawatimmy's answer aren't wrong, but the points made in the original post are also well taken. As your decision to post this question in this forum illustrates, this is also a quintessentially political act.
These chemical and radioactive weapons seem unusual, complicated, and draw attention.
This is a feature and not a bug.
Another analysis is that it is intended that the organizations behind these hits are unambiguous and that each hit is intended to send a loud and clear message to others similarly situated about who is ready, able and willing to kill you if you don't behave.
When you choose to kill with polonium-210 or a nerve gas agent, you are making it unambiguously clear that this is an officially sanctioned killing by an agency of a sovereign government that has access to these kinds of weapons. There is no room to suppose that this was a hit ordered by a jealous lover, or as a consequence of a drug deal gone bad, or by an anti-government faction. The method, together with the identity of the victim and to the extent discernible (as in the Korean case where the dupes who actually carried out the killing swiftly reported that their handler was Korean IIRC) the ethnicity of the perpetrator, leaves little room for reasonable doubt regarding who is responsible, short of an official public statement that the government carried out the killing, which even then could be doubted.
Also, the novelty of the method of assassination ensures that the hit becomes international news that is available to everyone else whom that government might want to exert pressure upon in the future (and a link to a verifiable third-party news clip could send the same message to hermits living on rocks who didn't catch this news the first time around).
These are all individuals who are being assassinated for suspected or actual disloyalty or insubordination of some form, and a public identifiable, high profile hit tells others who might consider disloyalty or insubordination that even if it seems like they are in the clear, that they can be made to suffer a horrible death at any time as a consequence of their disloyalty or insubordination and that the agency of the sovereign government to whom they owe loyalty won't hesitate to do it. It demonstrates that this agency has no scruples when it comes to disciplining its own.
After a few incidents like this, a mere photograph of the recipient or a member of their family, sent in a letter postmarked in a city associated with the agency to which the recipient might consider being disloyal or insubordinate could be enough to trigger terror in that person sufficient to secure their obedience, because it would demonstrate that they have the ability to kill the recipient since they know where the recipient lives.
Essentially, this is the same kind of showy, disgust inducing tactic seen in similarly overblown killings in fictional stories like the delivery of the dead horse head in The Godfather, or even more gory acts in the same vein in Game of Thrones.
The Latin phrase associated with this tactic when used in the Roman empire by some of its less scrupulous Caesars was: Oderint Dum Metuant ("Let them hate so long as they fear.")
Something possibly supporting this theory is how spokespeople eg state TV presenters make clear public warnings or threats to would-be double agents or "traitors" following these cases, for example recently http://www.bbc.co.uk/news/world-europe-43330498 *"I don't wish death on anyone, but for purely educational purposes, I have a warning for anyone who dreams of such a career: The profession of a traitor is one of the most dangerous in the world... Don't choose Britain as a place to live... too many strange incidents with grave outcomes".* Not proof, but it certainly fits the theory.
Non-state actors can and do commit gas attacks, at least with Sarin. Novichok, maybe not.
@gerrit They do *try*, but they really are not very good at it. Handling and deploying nuclear or nerve agents is not remotely easy (and we should be thankful for that).
@DavidRicherby Aum Shinrikyo wasn't very adept at deploying the gas, do so more or less randomly, and importantly, was the only group without a connection to a sovereign state to use such a method in history. While not absolutely impossible for a non-state actor to use, the method when combined with the nature of the victim, still makes responsibility clear enough to the people who matter, and public statements like those mentioned by user568458 seal the deal.
I was just adding information to @gerrit’s comment and wasn’t disputing it or your answer.
Not just willing and able to kill you, but willing to go to rather extreme measures to do so. Stabbing/shooting someone is rather straightforward. It takes a lot more effort to successfully orchestrate obtaining, transporting and delivering such agents. This is not an off-handed attack, but a carefully planned and choreographed one. The message is not just "we'll kill you" but "we will spend significant time, effort and resources to do so".
@R.M. also, stabbing or shooting someone might happen due to other causes: a jealous lover, a mugging gone wrong, or just a terrorist or psychopath attacking random victims.
Friend of mine posted something on Facebook earlier about this. "Ok Mr.Putin, how would you like us to kill him? Gun shot? Car accident?" - "No. Use a nerve gas agent that can be traced back to Russia". At least if they used the more traditional means you could use the line "It was the worst case of suicide I've ever seen".
@mickburkejnr Maybe I am missing your point here but that's what this answer is basically saying. No one can prove who ordered this killing but it's likely meant make a point to the world. That point is: "This is what happens to people who cross us. They die a horrible painful death and no one can stop us from doing it."
@JimmyJames You're attributing a theory that says a country, known for secrecy, cloak and dagger operations and subterfuge, went out of it's way to publically show to the world that they conducted a murder using chemicals in an act that could be seen as an act of war. I'm suggesting that I would think Russia, if they did do it, would be a little more secretive and silent about conducting such a thing. I'm sure the idea of a number of former Russian spies all dropping dead would be enough of a "F**k you" from Russia to those crossing them.
@mickburkejnr The theory that they're trying to make a statement makes a lot more sense than any of the alternatives. And, Putin's Russia has a long track record of making blatant statements that the Soviet Union did not. In the same vein, you could never make sense of Trump's motivations in political tactics, love him or hate him, but looking at the precedents of prior Presidents. Both men have broken dramatically with past precedents in their political and diplomatic tactics. The failure to go the final step and official admit the assassinations is just a form a gaslighting.
@ohwilleke-"you could never make sense of Trump's motivations..." I'd say a solid 40% of the country would disagree with that statement. It isn't hard to figure out the what/why once a person removes their bigotry and irrational beliefs from the equation. "broken..past precedents..." - Trying every way possible to do what you said you'd do instead of just saying things to get votes is already breaking with past precedents by orders of magnitude. That one difference alone dwarfs any other precedents Trump has broken.
@mickburkejnr All of this is conjecture on all sides. It's possible that some other actor has done this in order to make Russia look bad. We can come up with all kinds of conspiracy theories and none of it can be proven. I doubt anyone will ever know for sure. That's part of why this answer is plausible to me. Killing someone with a banned nerve agent and not getting caught is pretty damn 'cloak and dagger'. No one can directly pin this act on Russia but people will assume it was them and that's useful to make other potential defectors fearful.
@Dunk "I'd say a solid 40% of the country would disagree with that statement" I don't think so. The people who love Trump like him because he is a bold break from previous politicians, not because he's doing the same things that previous Presidents have done in the past.
But the question is, if you want attention why not just kill using a conventional weapon and then publicly proclaim you did it? That is, have the president of such a nation publicly announce on international TV, "We, the government of the nation of ABC sent a gunman to murder XYZ and did so (holds up the murder weapon in front of millions and billions on live TV)". If you don't want it overt, then why are you trying to make "clear" through the method what it is? Why not just not raise anything at all? Why the seeming halfwayism? Why not be _THAT_ direct?
@The_Sympathizer: as the OP wrote, `These chemical and radioactive weapons seem unusual, complicated, and draw attention.`. Occam's Razor implies that this is *exactly* the reason they were used in the first place. The only counter argument would be that a 3rd party is trying to put blame on Russia, but I fail to see how that could be *any* use at all - the world surely already believes that Russia is prepared to do almost anything in the "cloak & dagger" department, a 3rd party would surely gain little by adding to this opinion.
@The_Sympathizer (1) Credible signaling. You can lie about responsibility, but if you use a tool that only you own, you aren't lying; and (2) public, official acknowledgement has legal consequences that a credible signal that is officially albeit half-heartedly denied does not.
"Another analysis is that it is intended that the organizations behind these hits are unambiguous and that each hit is intended to send a loud and clear message to others similarly situated about who is ready, able and willing to kill you if you don't behave." Can you prove that? I mean, isn't alleged "unambiguousity" just like asking to fake it and then blame a state you want to force repercussions on?