Let's not forget, when the Moscow theatre was taken over Russia's premier counter-terrorist team decided to just gas everyone in the place with a super-secret aerosolised anaesthetic, hostages included. Then, because it was so secret, they didn't tell the medical teams on stand-by what it was which in turn led to 130 odd of the hostages dying from the effects of said agent.
So God knows what they'll unleash on IS if it does turn out to be a bomb that brought the aircraft down.
We fight them with one hand tied behind our back by treaties and conventions. Russia don't care about any of that crap.