Well, it's going to be a country with a highly developed chemical weapons program, or a client of said country. Realistically, the country which produced the chemical has to have given their blessing for it's use if a client country was involved.
Therefore, US, UK, Russia, China - at a guess.
Then it's a case of cui bono. I'd suggest that the UK doesn't have much to gain, the US no longer has anything resembling a coherent foreign policy, but the parts of the administration that would be able to do this are the parts that seem unlikely to attack an ally's major city with a nerve agent.
Russia or China, therefore - and I can't see a positive benefit in this for China.
Well, it's going to be a country with a highly developed chemical weapons program, or a client of said country. Realistically, the country which produced the chemical has to have given their blessing for it's use if a client country was involved.
Therefore, US, UK, Russia, China - at a guess.
Then it's a case of cui bono. I'd suggest that the UK doesn't have much to gain, the US no longer has anything resembling a coherent foreign policy, but the parts of the administration that would be able to do this are the parts that seem unlikely to attack an ally's major city with a nerve agent.
Russia or China, therefore - and I can't see a positive benefit in this for China.