Duncan Spinner has worked in conflict and post conflict operations and capacity building since 1992, initially as an officer in the British Army, where he commanded and planned a variety of counter terrorist operations as well as military diplomatic missions to build counter narcotics capacity in Colombia, counter poaching in Kenya, the application of the rule of law in internal security operations in Jordan and Israel and anti terrorism capacity in the US military after the suicide bombing of USS Cole in 2000. He raised, trained and led an Iraqi National Guard battalion conducting counter insurgency operations during the Mehdi army uprising in Basra region in 2004 before becoming a staff officer attached to the UK Department for International Development and the Foreign and Commonwealth Office building training capacity in the Balkans through the medium of The Peace Support Operations Centre.
Immediately prior to joining the ICMP in December 2013, he worked in the private sector on Kyoto protocol implementation across the Balkans and worked for NATO, where he was the senior NATO advisor to the Bosnian Ministry of Security on Counter Terrorism policy, Cyber Security and other emerging security challenges, with a particular focus on Crisis management and civil emergency protection. He was the NATO lead on designing and implementing legislation, policy and process for a successful Bosnian army officer selection process based on leadership potential and merit, a process which was described by Deputy Supreme Allied Commander Europe as "the most important piece of defence reform in BiH in 10 years