Answer
The answer to who sponsored Laurent-Désiré Kabila's rebel group is Rwanda and Uganda. They played a crucial role in supporting Kabila's Alliance of Democratic Forces for the Liberation of Congo-Zaire (AFDL) in their fight against the regime of Mobutu Sese Seko. The backing from these neighboring countries provided military, financial, and logistical assistance that ultimately led to the capture of Kinshasa and Kabila's rise to power in 1997.