Peacekeepers beginning to concentrate on church service? There's indifference (9)
I believe the answer is:
unconcern
'indifference' is the definition.
('unconcern' can be a synonym of 'indifference')
'peacekeepers beginning to concentrate on church service?' is the wordplay.
'peacekeepers' becomes 'un'.
'beginning to' says to take the initial letters.
'church' becomes 'ce' (abbreviation for Church of England).
'service?' becomes 'rn' (abbreviation for Royal Navy).
The initial letter of 'concentrate' is 'c'.
'un'+'c'+'on'+'ce'+'rn'='UNCONCERN'
'there's' acts as a link.
(Other definitions for unconcern that I've seen before include "Apathy" , "Lack of interest" , "Calm" , "Indifference" .)