Ross joined the British Foreign Office and worked at the UK embassy in Bonn, Germany before moving to the UK mission to the UN, where he worked from December 1997 to June 2002. At the UN, Ross served as the UK delegation's expert on the Middle East. Ross also worked on several important Security Council resolutions such as SCR 1284 which rewrote the Council's Iraq policy and established UNMOVIC, the weapons inspection body. He also negotiated for the UK the resolution establishing the International Security Assistance Force (ISAF) in Afghanistan and the Council's resolution of 12 September 2001 condemning the attacks of the day before. Ross then served as Strategy Coordinator for the UN in Kosovo (UNMIK) where he devised and led a joint UN and government policy to implement a series of standards to improve governance, the rule of law and human rights protection, and advised the Secretary-General's Special Representative on diplomatic and political tactics.
He left the British civil service in 2004 after 15 years of service. He is now a supporter to the UN Parliamentary Assembly. In 2004, he founded the non-governmental organisation Independent Diplomat, the world's first non-profit diplomatic advisory group which advises marginalized countries and groups around the world http://www.independentdiplomat.org/