How did muslim rulers in africa justify slavery?

The spread of Islam into Africa during the seventh century, however, ushered in an increase in slavery and the slave trade. Muslim rulers in Africa justified enslavement with the Muslim belief that non-Muslim prisoners of war could be bought and sold as slaves. As a result, between 650 and 1600, Muslims transported about 17 million Africans to the Muslim lands of North Africa and Southwest Asia.

the main reason the us senate rejected the treaty of versailles was because "european nations wanted to punish germany"

d(:

me and mark as brainliest.