Forum:Info regarding Big Boss's role in Mozambique war of independence

The same war where he first met Gray Fox (Frank Jaegar) as a child soldier prior to MPO. What I want to know is what was Big Boss's role in that war, was he with the guerrilla freedom fighters groups who were fighting for independence or was he with Portuguese? I think MGS4 Database, MGS4 Strategy Guide or MPO Strategy Guide does have an answer. Please tell me about his role and also tell me give the source of the answer. Thanks.