Desperate situations increase in Civil Service (6)
I believe the answer is:
crises
'desperate situations' is the definition.
(I've seen this before)
'increase in civil service' is the wordplay.
'increase' becomes 'rise' (rising is a kind of increasing).
'in' means one lot of letters goes inside another.
'civil service' becomes 'CS' (abbreviation).
'rise' put into 'cs' is 'CRISES'.
(Other definitions for crises that I've seen before include "Catastrophes" , "Moments of panic" , "desperate times" , "desperate situations" , "Times of great danger" .)