Robertson joined the Royal Air Force in 1966. He was appointed
Officer Commanding No. 92 Squadron flying
Phantoms in
West Germany in 1982 and then Officer Commanding
No. 23 Squadron flying Phantoms over the
Falkland Islands in 1984. He was then made Station Commander at
RAF Wattisham in 1985, Director of Air Staff Briefing and Co-ordination at the
Ministry of Defence in 1987 and Director of Defence Programmes at the Ministry of Defence in 1990. He went on to be Deputy Commander of
RAF Germany in 1991, Air Officer Commanding
No. 2 Group in 1993 and Assistant Chief of Defence Staff (Programmes) at the Ministry of Defence in 1994 before taking up his last appointment as Chief of Staff and Deputy Commander-in-Chief at
Strike Command in 1996; he retired in 1998. ==Other roles==