To start with, Ben embraces Joe (5)
I believe the answer is:
begin
'to start with' is the definition.
(I've seen this before)
'ben embraces joe' is the wordplay.
'embraces' indicates putting letters inside.
'joe' becomes 'GI' (GI Joe).
'ben' placed around 'gi' is 'BEGIN'.
(Other definitions for begin that I've seen before include "Partly open" , "Found" , "Monachem --" , "Get cracking" , "Make a start" .)