IS Group Says Plane Bombed Over Russian Involvement In Syria
https://www.youtube.com/watch?v=qBTOntxgq3Q
I never had any doubt that this was the reason. Now Russia needs to find the perpetrators (Ground Crew at the Egyptian airport) and kill them and their families.
As a matter of fact, I think the idea of killing all members of the immediate families of terrorists is a very functional and effective methodology.
If you follow this policy consistently and make it known, you create the conditions where families will kill their own rather than let them endanger the whole family.
Ergo, much less terrorism.