His presidency endured eight years through a combination of external backing and internal terror, with France and the United States providing material support in exchange for his role as a bulwark against Muammar Gaddafi's Libya. The instrument of his domestic control was the Documentation and Security Directorate, whose systematic abuses — documented in detail after his fall — eventually made him the subject of a landmark African prosecution. A Senegalese court convicted him of crimes against humanity and war crimes in 2016, making the case one of the first in which an African head of state was tried on the continent for atrocities committed during his rule.