Alex is able to stop Menendez from controlling the drones with the aid of his son David Mason and other significant individuals, preventing a global catastrophe. Another conclusion, known as the "Bad Ending," has Alex failing to stop Menendez, resulting in extensive destruction and the demise of important individuals.

Call of Duty: Black Ops II All 8 Endings (Best, Bad, Worst, kill/Spare Menendez) - YouTube.