Strategist recommends discretion in dealings with CIA (9)
I believe the answer is:
tactician
'strategist' is the definition.
(I've seen this before)
'discretion in dealings with cia' is the wordplay.
'discretion' becomes 'tact' (tactful can mean discreet).
'in' is an insertion indicator.
'dealings with' becomes 'in' (I am not sure about this - if you are sure you should believe this answer much more).
'in' going around 'cia' is 'ician'.
'tact'+'ician'='TACTICIAN'
'recommends' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for tactician that I've seen before include "One planning" , "Someone skilled in manoeuvres" , "General" , "One deploying forces in war" , "Skilful mover" .)