In 1975 he transferred into the Special Air Service. He was a lance corporal in 1980, serving in Pagoda Troop, 'B' Squadron, 22 SAS Regiment, when he led "Blue Team" in the storming of the Iranian Embassy in London during a hostage siege on 5 May 1980. McAleese fought in the Falklands War in 1982, and in The Troubles. He was awarded the Military Medal for gallantry in action at the Loughgall ambush in County Armagh on 8 May 1987, and was present at the Drumnakilly ambush in County Tyrone in August 1988. He also served as a bodyguard for three Prime Ministers of the United Kingdom. He was discharged from the British Army on 8 February 1992 with the rank of staff sergeant.