Conversation so far:
what is the only country that is not a member of the african union?
Morocco withdrew from the AU’s predecessor, the Organisation of African Union, in 1984. Morocco rejoined the Africa Union in January 2017, 32 years after leaving the union's predecessor, the OAU.

Question: what was the reason for leaving?
Self-contained rewrite: what was the reason for Morocco leaving the African Union in 1984?