In his early service years, he was involved in various operations including tours in Belfast (1978), the Falklands (1982), Crossmaglen (1983), South Armagh (1990), Northern Iraq (1991) and Angola (1992).

[4] In 2001 he became Director, Balkans in the Ministry of Defence and handled issues arising from the Insurgency in the Republic of Macedonia and relations with the International Criminal Tribunal for the former Yugoslavia before being posted to Iraq as Director Plans, Coalition Military Assistance and Training Team, Baghdad in 2003.

[5] Salmon was appointed an Officer of the Order of the British Empire in the 2004 New Year Honours and,[6] in December 2006, was granted permission to wear the Bronze Star Medal he had received from the United States "in recognition of gallant and distinguished services during coalition operations in Iraq".

He was deployed as General Officer Commanding Multi-National Division (South East), Iraq in August 2008.

He became Director of Force Readiness and Generation in NATO in 2010 and built their new Comprehensive Crisis and Operations Management Centre.