Not broken during diplomacy (6)
I believe the answer is:
intact
'not broken' is the definition.
(I've seen this in another clue)
'during diplomacy' is the wordplay.
'during' becomes 'in' (e.g. during February means in February).
'diplomacy' becomes 'tact' (tact can mean diplomacy or sensitivity).
'in'+'tact'='INTACT'
(Other definitions for intact that I've seen before include "Whole and unharmed" , "Unscathed" , "Undiminished" , "Flawless" , "Undamaged, unimpaired" .)