Time pressure on in war zone (7)
I believe the answer is:
theatre
'war zone' is the definition.
(I've seen this before)
'time pressure on' is the wordplay.
'time' becomes 't' (abbreviation).
'pressure' becomes 'heat' (I've seen this before).
'on' becomes 're' ('on' can be mean 'with reference to').
't'+'heat'+'re'='THEATRE'
'in' is the link.
(Other definitions for theatre that I've seen before include "Place of entertainment" , "Where dramas may be" , "Globe, say" , "Venue for plays, films and surgery" , "Scene of operations or dramatic performances" .)