So you can simultaneously deny it (as you can't politically take responsibility for it), and leave people in little doubt that it was actually you. The only mot

So you can simultaneously deny it (as you can't politically take responsibility for it), and leave people in little doubt that it was actually you. The only motive I can see to kill an old ex-spy (who by now could have leaked any information) is to send a message to your current spies, that defecting will mean you and your family get killed.