Maybe you're right, but I can't imagine how the assassination attacks would gain Putin enough to warrant doing them, especially since a chemical weapons attack on UK soil is arguably an act of war against the Brits. That would be, let's say, historic.
Russia have been testing a few countries for the last 6 or so years now (america included!)
From flying past our aviation borders, cyber attacks, assassinations, invading countries etc
They are simply trying to see what they can get away with IMO
This latest situation is basically a big FU and a message to say:
1. we will do what we want.
2. Anyone who is a traitor or an enemy of the state, you will die.