BTW, blinky, I apologize for completely hijacking this thread and causing your riddle to be ignored. Here is a solution:
I have taken the liberty of changing the demographics a bit to fit my sensibilities (Joseph would understand).
1) 2 Cannibals (C) take the boat across the river.
2) 1 C heads back
3) 1 C and 1 Marauding Imperialist (MI) take the boat across the river.
4) 1 C heads back
5) 2 MI take the boat across the river
6) 1 C takes the boat back
7) 2 C take the boat across the river
8) 1 C heads back
9) 2 C take the boat across the river
10) The Marauding Imperialists instruct the scribe to omit from the story any mention of the revolvers, rifles, and bayonettes they were carrying so as to misdirect the reader’s sympathy. It’s just a small band of harmless white guys now, scared to death of the vicious cannibals.