Gill is specialised in the law of armed conflict, the law governing the use of armed force and law of military operations. He was member of faculty at the NLDA since 2005 alongside his chair in military law at the UvA, which he has held since 2001. Gill’s research group within ACIL includes members of the staff of the NLDA which has a cooperation agreement with ACIL since 2010. The mayor referred to Gill's successful work in "putting the International Law of Military Operations on the map”. The mayor elaborated that Gill's contributions to legal science, the armed forces and Dutch society were the reasons for his national and international colleagues to nominate him for this distinction.
Terry Gill's farewell speech entitled "ILMO: The 'Flux Capacitor' of Contemporary Military Operations" is available for download from the NLDA website.