Harland was appointed HD's Executive Director in 2011.[4] In 2018, he publicly announced that the Basque armed group ETA had dissolved itself as the final step in a long-running process to bring an end to violence in the Basque country.[5][6]
In 2022, Harland and HD were cited as an initiator of the UN-brokered deals to ease the global food crisis by facilitating agricultural exports from Russia and Ukraine.[7][8]
HD was awarded the Carnegie Wateler Peace Prize for 2022 "for its more than 20-year track record in ending armed conflict and for its patient, creative and discreet approach”.[9][10][11]
Harland also sits on the UN Secretary-General's High-Level Advisory Board on Mediation and on the Scientific Advisory Board of the Robert Koch Institute Centre for International Health Protection (ZIG).[12][13]
Before joining HD, Harland was director of the Europe and Latin America Division of the United Nations Department of Peacekeeping Operations (2006–2011), where he managed the end of the UN transitional administration in Kosovo.[15]
He served in UN peacekeeping missions in Haiti (2010),[16] in Kosovo (2008),[17] in Timor Leste (1999–2000), where he set up and oversaw what would be the first government departments,[18] and in Bosnia and Herzegovina (1993–1998), where he co-led (with the Office of the High Representative) the post-war effort to increase freedom of movement through the introduction of a new national license plate, which he designed.[19]
Harland served as a witness for the prosecution at the International Criminal Tribunal for the former Yugoslavia in the cases of The Prosecutor versus Ratko Mladic[23] (2012), The Prosecutor versus Radovan Karadžic[24][25] (2010), The Prosecutor versus Dragomir Miloševic[26] (2007) and the Prosecutor versus Slobodan Miloševic[27] (2004).
He was a script advisor for the Oscar-nominated film Quo Vadis, Aida? (2019–2020)[28]
"Post-Dayton Bosnia and Herzegovina", With Elizabeth Cousens, In William J. Durch, ed., Twenty-First-Century Peace Operations. Washington, D.C.: United States Institute of Peace Press (2006): 49–140.
"Kosovo and the UN", 'Survival: Global Politics and Strategy', volume 52, number 5, October–November 2010, pp 75–98.