Born in December 1944, he retired from the Nigerian Army as a Major General. Alli served as Chief of Army Staff from 1993 to 1994 during General Sani Abacha’s regime and held the position of military governor of Plateau State, Nigeria, from August 1985 to 1986 under the military regime of General Ibrahim Babangida.
Following ethno-religious killings in Shendam, Yelwa Local Government, he was appointed interim administrator of Plateau State during a 2004 crisis.
After retiring from the military, he authored a book titled 'The Federal Republic of Nigerian Army: The Siege of a Nation.' General Alli clarified that the book was not an indictment of the military but his perception of his generation's conduct and the various forces at play during that time.
Before his demise, General Ali also served as a member of The Guardian Editorial Board.