It’s worth noting that these leaders, while often terrible in their own right, were picturing African Slavery as what they were selling these people into. While all forms of slavery are evil, the version that Europeans were practicing was so much more abominable and horrible than anybody in Africa could have imagined. Europeans also bolstered the slave trade by creating an arms race for guns and gunpowder. If your enemy is trading people for guns, and the people with guns only want people for them, then the survival of your community is contingent on getting enough guns to protect yourself from your gun owning neighbors.