Educated at
Culford School in
Suffolk, England, McColl was commissioned as a
second lieutenant in the
Royal Anglian Regiment in 1973 and promoted to
lieutenant on 8 September 1974. He was promoted to captain on 8 March 1979 and to major on 30 September 1984. In 1989, he became a squadron commander in the 3rd
Royal Tank Regiment, was promoted to lieutenant colonel on 30 June 1990, and to acting colonel shortly after. He was promoted to colonel on 30 June 1995 and to brigadier on 31 December 1996 (seniority 30 June). He held a variety of commands and military posts before commanding
1st Mechanised Brigade in 1997. In 1999, he became Assistant Chief of Staff at
Land Command and in 2000, he was given command of
3rd (UK) Mechanised Division. In 2001, he was appointed the first leader of the
International Security Assistance Force in
Afghanistan. In 2003, he became
Commandant of the
Joint Services Command and Staff College. He was deployed as
Senior British Military Representative and Deputy Commanding General, Multinational Force, Iraq in March 2004 and at the end of that year he became
Commander of Regional Forces at
Land Command. He became
Deputy Supreme Allied Commander Europe (DSACEUR) in the rank of
general in October 2007, and was appointed
Knight Commander of the Order of the Bath (KCB) in the
2008 New Year Honours. McColl was the preferred choice of Afghanistan for the role of UN Special Envoy after
Paddy Ashdown withdrew. However, on 7 March 2008, Norwegian diplomat
Kai Eide was appointed as the UN Special Representative for Afghanistan. McColl retired as DSACEUR in March 2011. ==Lieutenant Governor of Jersey==