Answer:
At that time, European traders need a massive increase of cheap labors to be put on their plantations and mines . So, they targeted people from Africa to be used as slave labors.
But, they realized that actually attacking the village and acquiring the slaves will caused a lot of damage for them.
Barbon stated that The European realized that there were intense rivalries between leaders in West Africa. So, the European decided to took advantage of this. They cooperated with a lot of African leaders to capture the members of their position and sold it to them. By doing this, the European could fulfill their slaves quota without getting their hands dirty.
In the end, this resulted in massive economic growth for the European and massive economic stagnation in African regions since they're basically manipulated to tore each other apart.