Slaves started the new colinies econamy. They were free laboros that tended to the land for cheaply or no cost at all. Due to this, the colonist were able to sell goods back to the main land for a low price and was able to maintain a plentiful food supply for little or no cost to them.
It would be because the atomic bomb was a new superweapon, and napalm had been around for a while. Does that make it right? No, but what had to be done had to be done.
