McManners then passed the year-long Army Staff College course at Camberley. He was promoted Major in 1985,and spent two years working at the Ministry of Defence in London. He has served at Fort Ord California with the US Army's 2nd Infantry Division (Light), on counter terrorist duties in Armagh, Northern Ireland, and with the United Nations in Cyprus during the Turkish invasion of 1974. After commanding 17 Corunna Field Battery , he retired from the Army in 1989.