I guess one of the important considerations (especially relevant for persons from western democracies) is if he will likely feel 'trapped' by rank and/or money down the track.
I know many pilots in the ME who would desperately love to return home to America/Canada/UK/Ireland/Australia/NZ/Sweden/Germany etc but feel they can't possibly do that because they couldn't tolerate the large take-home pay reduction and lower rank that will accompany a move to the bottom of a seniority list back in their home country.
PG