Raiding civilians for the greater good of... what?
The human race. I'm not saying it was the best choice but everything Cain did was out of fear and for the ship. She wasn't some greedy Cheney figure that stood to gain money and power from the conflict.
It's why I don't think BSG's social critique of the War on Terror really worked. Iraq had no nuclear weapons and were no threat to America. The Cyclons had just wiped out most of the human race in a nuclear holocaust. It made that type of behaviour far more reasonable.