Pressure to abandon agreement? It may be just a pose (3)
I believe the answer is:
act
'it may be just a pose' is the definition.
(act can mean a pose or pretence)
'pressure to abandon agreement?' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'to abandon' suggests deleting specific letters.
'agreement?' becomes 'pact' (pact is a kind of agreement).
'pact' with 'p' taken away is 'ACT'.
(Other definitions for act that I've seen before include "Bill successfully prosecuted" , "law passed" , "Perform on stage" , "Thing done" , "Take steps" .)