Date when surveillance operation doesn't start (4,3)
I believe the answer is:
take out
'date' is the definition.
(to take someone out is to date them)
'surveillance operation doesn't start' is the wordplay.
'surveillance operation' becomes 'stake out' (as in staking out a location).
'doesn't start' means to remove the first letter.
'stakeout' with its initial letter taken off is 'TAKE-OUT'.
'when' is the link.
(Other definitions for take out that I've seen before include "Remove from within" , "kebab, perhaps" , "Extract; kill" , "Bump off" , "As gangster, kill" .)